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 theunblock_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.

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 thiswebsite 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?

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 .dllextension 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 ?

Please pass your comments and tell me your opinion. I am just waiting for your comments. 

Have you accidentally deleted your files from the hard disk? Do you desperately need to recover the deleted files back in the original form? Well, you need not panic!

It is possible to recover the deleted files or data back from the hard disk  (even after you have Shift+Deleted)  provided you act as soon as you realize that the files are deleted and use the best deleted files recovery software.

In this post you will find a detailed information on how to recover the deleted files back from your Windows PC or Mac.

How Deleted File Recovery Process Works?

When you delete a file from your computer, (or even from the recycle bin) the file is not actually deleted. Unlike what most people think, whenever a file or data is deleted from your computer, it is not permanently vanished or dropped out from your hard disk. Even though the files appear to have been deleted, they can still be recovered successfully.

Let’s take up a small example of a book containing 50 pages. Suppose when you delete the page 25, assume that only the entry in the index which points to the page 25 is deleted and not actually the page 25 itself. Likewise, when you delete a file from your hard disk, only the pointer which points to this file is removed and not actually the file itself. This file still exists intact and is 100% possible to recover it back in the original condition. In this condition, the file becomes invisible and hence appears to have been deleted.

Recovering the deleted files 100% back in the original condition is very much dependent on the efficiency of the data recovery software you use. So, it is necessary to make a right choice when it comes to the selection of file recovery software.

Today, there exists hundreds of data recovery tools and software programs on the market which boast to recover 100% of all the deleted files back in the original condition. But in reality, most of these programs are neither effective nor capable of recovering your files back. So, when it comes to Data Recovery, I recommend the following program as the best:

1. Stellar Phoenix Data Recovery (for Windows)
2. Stellar Phoenix Mac Data Recovery (for Mac)

Stellar Phoenix is one of the best company specializing in deleted files recovery services and solutions since 1993. Stellar’s Data Recovery Solutions encompasses a wide range of software for almost any data loss situation ranging from accidental formats to virus attacks to software malfunctions. Hence, Stellar provides the best tools to recover deleted files with over 1,000,000 satisfied customers across 137 countries.

What are the Chances of Recovering my Files Back?

Since the operating system doesn’t immediately re-use the space from the deleted files, it is most certainly possible to recover the deleted files back in 100% original condition. It may take up a very long time for those files to be completely deleted since the modern hard disks have ample capacity. Hence the chances are too less that the space from the deleted files are re-used immediately.

So, it is really worth to try out the file recovery software like Stellar Data Recovery for Windows orStellar Data Recover for Mac. Some files are reported to have been recovered even after years of its deletion. However, for the best results, it is recommended that you use the file recovery software as immediately as possible.

Recovering the Deleted Files:

In order to recover the deleted files, all you need to do is perform a scan (search) for the deleted files using a File Recovery Software. Please be informed that there is no manual way to recover the deleted files. The Phoenix Data Recovery software performs a thorough scanning of the hard disk sector by sector and will locate the existence of deleted files to restore them back in the original condition. It is the only software that supports 185 popular file types including Windows NT Registry, JPEG, MP4, GIF, BMP and MS Word files. The software offers rich graphical support and incorporates advanced scanning methods to completely scan and recover deleted files from your hard drive. With this recovery software, it is possible to

• Recover FAT16, FAT32, VFAT, NTFS, and NTFS5 file system partitions
• Recover deleted emails
• Recover deleted documents
• Recover deleted photos
• Recover deleted music
• Formatted Hard-Drive recovery
• Recover files from USB Drives, CDs, DVDs and memory cards
• Recover almost all the camera format files

Visit the following links for more information on Stellar Data Recovery:

Stellar Phoenix Data Recovery (for Windows)

Stellar Phoenix Mac Data Recovery (for Mac)

Ever wondered to know how to hide secret data in image, audio and video files? Well, in this post I will take you through a concept calledsteganography using which, it is possible to hide your secret information in image files, songs or any other file of your choice. At the end of this post, you can also download free stegnographic tools and start hiding your data.

What is Steganography?

Steganography is a means of obscuring data where secret messages are hidden inside computer files such as images, sound files, videos and even executable files so that, no one except the sender and the receiver will suspect the existence of stealth information in it. Steganography may also involve the usage of cryptography where the message is first encrypted before it is concealed in another file. Generally, the messages appear to be something else such as an image, sound or video so that the transfer of secret data remains unsuspected.

The main advantage of steganography over other methods such as cryptography is that, it will not arose suspicion even if the files fall in the hands of a third party. Unlike cryptographic messages, stegnographic messages will no way attract the attention of a third party by themselves. Thus stegnanography has an upper hand over cryptography as it involves both encryption and obscurity.

What are the Applications of Steganography?

Steganography is mainly used to obscure confidential information/data during storage or transmission. For example, one can hide a secret message in an audio file and send this to another party via email instead of sending the message in the textual format. The receiver on the other end will decrypt the hidden message using the private decryption key. In a worst case scenario, even if a third party does manage to gain access to the email, all he can find is the audio file and not the hidden data inside it. Other usage of steganography include digital watermarking of images for reasons such as copyright protection.

Even though steganography has many useful applications, some may use this technique for illegitimate purposes such as hiding a pornographic content in other large files. Rumors about terrorists using steganography for hiding and communicating their secret information and instructions are also reported. An article claiming that, al-Queda had used steganography to encode messages in images and transported them via e-mails, was reported by New York Times, in October 2001.

How do Steganography Tools Work?

Stegnography tools implement intelligent algorithms to carefully embed the encrypted text messages or data inside other larger files such as an image, audio, video or an executable file. Some tools will embed the encrypted data at the end of another file so that there will be enough room for storing larger data.

There are many steganography tools available online but only a few are able to work flawlessly. I did not find any tool that worked perfectly on both small and large data. However, I have  managed to develop my own tool that can work perfectly on all types of files and all size of data. The tool is called “Stego Magic“. You can download it from the following link.

Download StegoMagic.zip

The zip file contains two versions of Stego Magic: One for encrypting the text messages and the other for encrypting binary files. StegoMagic_TXT can be used to hide text messages in other files such as an image or a sound file. StegoMagic_BIN can be used to hide one binary file in another such as an executable file inside an image or an image inside a video file.

With Stego Magic, there is no limitation on the size and type of the file that you are intending to hide. For example, you can hide a video of size 1 GB in an image of size 1 MB or hide an executable file inside a WORD document. The tool is pretty straightforward to use and requires no special understanding of the concept.

At the end of the encryption process, a secret decryption key will be generated and the same is required during the decryption process.

How to Use Stego Magic?

Suppose you want to hide a text message inside a JPG file:

1. Place the JPG and the text file (.txt) in the same folder as that of StegoMagic_TXT.exe
2. Run StegoMagic_TXT.exe and follow the screen instructions to embed the text message inside the JPG image.
   Please note that if you’re using Windows 7/Vista, right-click the file and select “Run as Administrator”. Otherwise the tool may fail to work properly.
3. Note down the secret decryption key.

Now you can send this image to your friend via email. To decrypt the hidden message, your friend should load this JPG file onto the Stego Magic tool and use the secret decryption key.

I hope you’ve now understood what is steganography and how to use it to hide your secret data. For queries and feedback, please pass your comments