The latest news is the “once infallible” Apple line of computers got sick. A virus called MacDefender is making the rounds.

While Windows users suffered through the virus-clean-patch cycle again and again, it seemed like Macs were immune. Apparently, the new-found popularity of Macs brought out the hackers.

This post is not a comprehensive guide to viruses. It is written to people who get bitten by computer viruses.

How Can You Tell If You Have a Virus?

Viruses are bits of code designed to implement hidden processes. Most are nuisances but some are destructive. Signs that a computer virus infected your machine are:

  • Slow performance. Web pages limp into view and simple tasks turn into minutes.
  • Strange screens. Recent viruses include a warning your computer is infected and for a small fee, it will clean your computer. In truth, it is just adding more junk to the junky system. The screens and notices look authentic, though some have misspelled words–the tip-off. (Sadly, too many novices fall for the ploy believing it comes from Microsoft and is genuine.)
  • Notices from friends. Many times, you will get notices from friends asking about strange messages. This is a signal that something has hijacked your address book and is sending out messages from another source in your name. (Some can be vile!)

How Did I Get It?

Usually people get viruses innocently. But three sources are common.

  • Opening a link in an email or a website. Many times, a link to a online video (even sent by a friend) is the trigger to “lock and load.” These links are everywhere–email, Twitter feeds, and Facebook mentions.
  • Downloading “free” software. I know of a friend who downloaded a program to insert emoticons (the smiley faces you see in emails). He did not pay financially, just through the grief of what was imported.
  • Through plugging in foreign media. At our church, we had one user who used a stick drive that was infected. The transfer was invisible but had noticeable effects on performance.

For most people, it’s not where it came from but what do you do for it once you get bitten by the virus. That’s the subject of our next post.