Peer-to-peer file sharing has become very popular these days. Users of all ages use these programs to expand their music collections, movie collections, or even game and program collections. There are many different peer-to-peer (P2P) programs that are used for file sharing, such as Kazaa, Bear Share, LimeWire, and BitTorrent, among others. Some have both free and paid versions of the software. Usually the “Free” versions come bundled with adware in order to pay for themselves. No matter which version you use, there are infections waiting to be downloaded.

I used Napster a bit when it first came out and ran it on my old Windows 98 machine with 64 megs of ram and dialup internet. It was slow going and I quickly lost interest. Nowadays, computers are much faster and there are a number of ways to get high speed internet. I recently installed a P2P program on one of our infecter machines and discovered how easy it was to get infected.

A careful and computer savvy person can avoid most infections, but some can sneak by even the most careful users. It is best to avoid any .zip files, especially when they contain an executable inside (such as setup.exe). These executables usually unleash a downloader that installs all kinds of malware onto your system. Most of the .zip files came up for games, software, and other programs.

Other files that are very likely to be infections are ones that have two extensions ending in .exe, such as cutegirls.jpg.exe. Most people may only see the cutegirls.jpg (which is an image extension) once the file is downloaded to their computer. This is usually due to the default setting where the computer does not show known file extensions, and therefore will not show the final extension, which is .exe (an executable). A computer will execute the last extension on the file, so if it were a .mp3.exe, or .txt.exe, it would execute the commands of the file, where as if it it were a .mp3.txt, it would try to open it as a text document. So, when a user clicked on the supposed image file cutegirls.jpg.exe to view it, they would actually execute the code of the file, which would infect the machine. 

There is also the chance that a file is infected even if it carries no noticable signs of being so. It is always best to scan a file with an antivirus software program before trying to open it. Always scan the files individually inside of an archive (or compressed) folder, as many scanners have trouble scanning inside of an archive. If you choose to use P2P file sharing programs, it is important to know that there are thousands of infections out there, and it is easy for them to exploit the P2P programs to further spread themselves. I advise all users to scan all their downloaded files before they try to use them, this will help prevent executing malicious files that may have been downloaded.