The year 2004 has been an erratic year with respect to malicious code. There have been serious epidemics such as those perpetrated by Sasser or Mydoom, and we have witnessed a cyber-war between groups of delinquents trying to get their creations -Bagle and Netsky- to circulate as widely as possible. Thankfully, there have also been periods of relative calm.
Now, as we approach the end of the year, Panda Software has drawn up a list of viruses that, for one reason or other, have stood out from the rest.
- The most damaging. There can be no doubt that Sasser takes first place here. It wasn't just responsible for one of the most serious epidemics seen so far, its effects were also especially annoying for victims who found their computers were virtually unusable due to the continuous restarts that this malicious code caused. The good news at least, is that the creator of Sasser has been apprehended.
- The most sophisticated. Not an easy choice, but we've gone for Noomy.A, a worm that constructs infected web pages and sends messages through chat channels as though it were a genuine user. It doesn't actually cause too many problems in computers, but it is nevertheless a technically complex worm.
- The most talkative. This was an easy choice, as it is the only one of its kind. This is Amus.A, a malicious code from Turkey that uses Speech Engine in the Windows XP operating system to announce its presence.
- The most musical. Not one, but several variants of the Netsky worm take the title here, as they emit a peculiar melody for three long hours once they have infected a computer!
- The shyest. This goes to variants of the Bagle worm, which sent themselves out in password protected ZIP files to prevent antivirus applications from scanning them when they enter a computer. The strategy is actually used by a lot of malicious code, but we have opted for the Bagle family given the extent to which they propagated throughout 2004.
- The most opportunist - the most polyglot. Zafi.D, a recent worm that many users will still remember, has all the qualities to win both categories. Designed to imitate a greetings message and therefore exploit the festive season, this malicious code spreads in messages in a multitude of languages.
- The smuttiest. Pornography has not been a commonly used theme this year, although there has been the odd exception. One of these was Tasin.C, which downloaded an erotic image of a famous Spanish celebrity.
- The most repetitive. This category is really dedicated to the creators rather than the viruses themselves. The prolific Gaobot family of worms saw its numbers increase by almost 2,000 new variants throughout 2004!
- The most schizophrenic. Bereb.C could use 442 different names to spread across P2P file-sharing applications. Even its creator probably couldn't remember the name of the original file.
- The politest. In this category we have selected not one, but three malicious code -StartPage.AV, Harnig.B and Multidropper.AM-. All of these are 'kind' enough to display a message to users informing them that their computers have fallen into their hands.
There is no doubt that there are so many viruses in circulation that users who don't take the right precautions are likely to end up with an infected computer. For this reason, Panda Software advises all users to protect themselves with a recognized antivirus solution and keep it up-to-date