In this guide I am going to show you how to create a professional antivirus program that scans for MD5 hashes. To get a better look on what you are going to make I will explain some things about MD5 hashes.

Every unique file on your computer has an MD5 hash. The MD5 hash can be used for different things such as

• Identifying the file as a virus by an antivirus
• Checking for duplicate files

An MD5 hash looks like this: 098f6bcd4621d373cade4e832627b4f6, it contains a total of 32 letters and numbers.

In this guide we will be creating a piece of software that compares the MD5 hash of a file with known MD5 hashes of bad files such as viruses, and will report to you if a match has been found. In no way should you use this software as a replacement of your real, commercial security software such as PC Tools IS 2011 or Kaspersky IS 2011.

To start the creation of your very own antivirus program you are going to need programming software. In this guide I will be giving you code that can be used in the programming software "Visual Basic 2010 Express Edition". This programming software can be downloaded from the following URL: http://www.microsoft.com/visualstudio/en-us/products/2010-editions/express. After you have installed it please take your time to get used to the programming environment by watching a couple of videos. I am not going to give away the full code in this guide because of possible errors so you will need to do some things by yourself. After you have gotten used to the coding software you can continue with the guide.

Your antivirus program has a few parts which should be coded:

• You will need to get the MD5 hash of a file.
• Your antivirus should compare the MD5 hash of the file with known bad MD5 hashes, so you will need to enter the MD5 hash found in the above step into a textbox, and then you should compare that textbox with known bad MD5 hashes by using: "If textbox.text = XXXXX then ... "
• If a match is found your antivirus should report it to you with a messagebox: Msgbox "Virus Found"

The layout of your antivirus is entirely up to you and I suggest you to watch a few videos on YouTube containing self made (fake) antivirus software that have a nice layout, to get some ideas: http://www.youtube.com/watch?v=-5VZj-yaVtw and http://www.youtube.com/watch?v=CQx-T3JtJg4&feature=related.