People who use peer-to-peer networks for purposes of downloading files (music, video, and software being the most common) should be very careful in their actions. Here are some basic rules:
- Watch your extensions: When downloading something, pay attention to the file extension. A movie with an .exe extension might not be a movie. It might be a zipped movie, but it might also be a virus. Make sure you use the proper filters when searching for things.
- Know your networks: There are many file sharing programs, networks, and standards so avoid the bad ones and use the good ones. Bittorrent is by far the best overall, but it will require a bit more effort and you might not find what you want. Shareaza uses three different networks and doesn't have as many security issues as other networks. In my opinion, it is by far the best P2P network around, short of Bittorrent.
Kazaa used to be the greatest file-sharing network around, if you used the third-party version that didn't have the spyware, anyway. However, it is a mere shadow of its former self and you're about as likely to get a worm from it as a useful file. There are a number of other P2P programs, but most of them just aren't as good or as safe as Shareaza or Bittorrent.
- Avoid sharing illegal stuff: Getting sued by the RIAA or MPAA isn't worth the risk. I think it's important to keep file-sharing network in good health by sharing files you download, but be careful.
Use a router for improved security - How much?
- Leave your firewall and virus on while sharing: Don't turn them off because they interfere with it; that's a good thing. Many file-sharing programs will give you worms just for using them if you don't have an anti-virus program running.
- Know the file size: If you're downloading a software program, but it's only six or seven hundred KB in size, it's probably a little virus. Some useful programs can be that small, but for the most part anything that small -- be it movies, music, or software -- it's probably not smart to be downloading.
Know who your mail is coming from. Don't open attachments unless you're absolutely sure what they are. Check the message body and the sender. Avoid opening emails unless you know who it's from. Also, avoid use of Outlook Express or similar email clients, if it's possible. It's necessary for many addresses, including many work and ISP addresses.
However, it's not necessary for something like a Yahoo or MSN address, and it's not necessary to use at all if you don't already have an email address. Outlook Express in particular is the source of many security vulnerabilities, and other mail clients can be just as vulnerable. At the very least, try to choose an antivirus program that scans email.