Protect Your PC From File-Sharing Dangers

Jan. 26 -- Peer-to-peer file-sharing networks have come a long way since the dawn (and demise) of Napster, with LimeWire, KaZaA, Morpheus, Grokster, and others offering everything from MP3 files to movies, software, and anything that can be exchanged across a digital network.

If you're using or plan to use such networks, you should know that copyright infringement isn't the only issue to consider. You also open up your system to a host of security and privacy threats, including viruses, worms, Trojan horses, snooping, data theft, spyware, and more.

The first thing to understand about file sharing is that every user's system acts as a server for everyone else's, so there is almost no way to control the content that is available on a network.

This makes it easy for anyone to distribute a virus, worm, or Trojan horse in a file you thought contained your favorite song. Once that file is in your file-sharing directory, it's usually available to everyone, whether you've tried to play it or not, so malware can spread very quickly.

Some of the software itself has been known to have Trojan horses and other security problems. And a number of file-sharing applications contain invasive adware that monitors your online behavior and sends data back to a server. Although providers are backing away from this lately, millions of users have unwittingly downloaded tons of spyware along with file-sharing apps.

Even if you aren't using your file-sharing application, it's usually up and running in the background, providing other users with access to your system — and often to your IP address.

Studies such as "Usability and Privacy: A Study of Kazaa P2P File-Sharing" (www.hpl.hp.com/shl/papers/kazaa/index.html) suggest that the majority of users don't know what files they're sharing and may inadvertently end up sharing private files such as e-mail and financial information.

Turn It Completely Off

There are a number of steps you can take to protect yourself. The most obvious step is to turn off your file-sharing app when you're not actively searching or downloading.