The number of new viruses released into the wild rose last year after three consecutive years of decline, according to anti-virus company McAfee.
Reporting the top 10 security bugs for 2004, McAfee said Bots and mass mailers were still the main threat to businesses.
Overall, the number of computer viruses rated medium risk or higher increased 130% from 2003.
McAfee said Bots - automated programs that answer to commands from another source - are growing at a rate of about 150 to 200 per week.
Vincent Gullotto, vice-president of McAfee’s Avert security response team, said, "Although we saw a steady 5% year on year decrease in the rate of virus production from 2000 to 2003, we saw an increase in 2004, which can be partly attributed to Bagle and Netsky authors feuding, as well as a general lack of awareness regarding adware and other programs."
McAfee’s top 10 threats for 2004, in alphabetical order, are:
- W32/Sdbot (family including sdbot, gaobot, polybot, spybot)
Rival anti-virus company Panda Software found the Downloader.GK trojan was the most widely circulated malicious code in 2004, responsible for 14% of all attacks.
The trojan is downloaded onto computers when unsuspecting users visit certain web pages and accept the installation of an ActiveX control. Downloader.GK installs and runs two adware programs on the computers it infects.
Panda said 2004 was the first year that a trojan rather than a worm headed the list and that that four of the top 10 were also trojans, when in 2003 there were two, and in 2002 just one.
Panda’s top 10 of malicious code are:
- Trj/Downloader.GK: 14%
- W32/Netsky.P.worm: 6.92%
- W32/Sasser.ftp: 4.97%
- W32/Gaobot.gen.worm: 4.31%
- Exploit/Mhtredir.gen: 4.22%
- W32/Netsky.D.worm: 3.98%
- Trj/Downloader.L: 3.56%
- Trj/Qhost.gen: 3.48%
- W32/Netsky.B.worm: 3.45%
- Trj/StartPage.FH: 3.34%