File Sharing (P2P), Torrents, Keygens, Cracks, Warez, and Pirated Software are a Security Risk
The practice of using any torrent, file sharing, peer-to-peer (P2P) program (i.e. Limewire, eMule, Kontiki, BitTorrent, BitComet, uTorrent, BitLord, BearShare, Azureus/Vuze, Skype, etc), keygens, hacking tools, cracking tools, warez, or any pirated software is a security risk which can make your system susceptible to a smörgåsbord of malware infections, remote attacks, exposure of personal information, and identity theft.
File Sharing, Torrents, and Peer-to-Peer (P2P) Programs
File sharing networks are thoroughly infested with malware according to security firm Norman ASA and many of them are unsafe to visit or use. The reason for this is that file sharing relies on its members giving and gaining unfettered access to computers across the P2P network. This practice can make you vulnerable to data and identity theft, system infection and remote access exploit by attackers who can take control of your computer without your knowledge.
...It is almost never safe to download executable programs from peer-to-peer file sharing networks because they are a major source of malware infections.
Software Cracks: A Great Way to Infect Your PC
Some file sharing programs are bundled with other free software that you may download (sometimes without the knowledge or consent of the user) and can be the source of various issues and problems to include Adware, Potentially Unwanted Programs (PUPs), and browser hijackers as well as dangerous malware. Users visiting such sites may encounter innocuous-looking banner ads containing code which can trigger pop-up ads and malicious Flash ads that install malware. Many malicious worms and Trojans, such as the Storm Worm, have targeted and spread across P2P files sharing networks because of their known vulnerabilities.
Even the safest P2P file sharing programs that do not contain bundled spyware, still expose you to risks because of the very nature of the P2P file sharing process. By default, most P2P file sharing programs are configured to automatically launch at startup. Some P2P programs are also configured to allow other P2P users on the same network open access to a shared directory on your computer by default. If your P2P program is not configured correctly, you may be sharing more files than you realize. Even if you change those risky default settings to a safer configuration, the act of downloading files from an anonymous source increases your exposure to infection because the files you are downloading may actually contain a disguised threat by hiding a file extension or adding spaces to the existing extension as shown here (click Figure 1 to enlarge). The best way to eliminate these risks is to avoid using P2P applications and torrent web sites.
Many security forums ask members to remove P2P software before assisting them with malware disinfection. The nature of such software and the high incidence of infection or reinfection is counter productive to restoring the computer to a healthy state...see here.
Using P2P programs, file sharing or browsing torrent sites is almost a guaranteed way to get yourself infected!!