Chapter 12. Securing Your Standalone PC: Viruses, Chat, and Encryption

Using applications on your PC poses threats that are separate from blatant attacks by hackers or marketing companies. The data on your computer, which is full of useful things about you, can be a target for destruction by automated attacks. The operating system is one form of protection, and firewalls are another, but when an intruder or automated attack gets past these defenses, you might also need to rely on virus scanning and encryption.

The home user market is the latest testing ground for the virus writers. In the past, it was rather hard to spread a virus quickly because the Internet connections were just not available. With the advent of broadband connections and the use of multiple technologies that allow you to share files and applications, it has become extremely easy for a virus to infect hundreds of thousands of computers in a matter of hours. You, acting as your own system administrator, have to take responsibility for virus scanning at home and keeping up-to-date with the latest releases of the software just as corporate system administrators have been doing for years.

Sharing of files, which could possibly be infected with a virus, can happen in a number of different ways. One popular method of sharing information is through Chat type services such as Instant Messenger, ICQ, and Yahoo! Messenger. Everything from viruses to denial of service attacks can be launched over these types of Internet applications. Many people assume that security is built into these types of applications, but just the opposite is true. Security was the least required feature in these sharing types of applications until recently.

After an intruder has access to your system, whether it's through a virus that can steal a file and mail it to the attacker or through the file upload capabilities built into the messenger/chat programs, your last line of defense becomes encryption. If an intruder breaches all of your security measures, encryption is the last and possibly strongest defense you can hope to have. With good encryption in place, even if you become hacked and all your files are stolen, you would not have to worry about the data being read by the attacker.