Computer users should brace for a new onslaught of viruses this year, especially worms deployed into instant messaging systems, an anti-virus expert says.
British-based Sophos, the fourth-largest anti-virus solutions provider, said it sees more viruses and their cousin, the self-propagating worm, infecting computers in 2003, but their occurrence was not expected to grow significantly.
"Virus writers are most interested in creating the next super Windows worm, spread by e-mail or instant messaging, as these mass-mailing viruses carry the greatest impact," Graham Cluley, senior technology consultant at Sophos, told a news conference.
"We expect more executable email-aware worms this year, while more viruses are written which use instant messaging services".
Popular instant-messaging systems include AOL Time Warner's subsidiary ICQ, Microsoft's Instant Messaging and a similar system run by Yahoo.
A spokesman for Sophos said it was not singling out any one particular software technology as vulnerable.
Sophos also expects to see a rise in the number of so-called "Backdoor Trojans", which open up holes in operating systems enabling hackers to implant Remote Access Tools that can operate an infected computer by remote control.