Devious viruses set to grow

Home users warned to watch out for viruses

Malicious viruses that use devious tricks to infect computers are set to become more common in the future.

Anti-virus software company Sophos found that the Nimda worm was the most widespread virus this year, even though it first appeared only in September.

There's 70,000 viruses in existence, we've got enough, we don't need any more

Graham Cluley

"Nimda was effective because it could infect computers with a variety of techniques," said Sophos senior technology consultant Graham Cluley.

"It is likely that we will see more multiple-pronged attacks in the future."

Sophos also warned that home users were increasingly likely to be the victim of hacker attacks, due to the growth of "always-on" high-speed internet connections.

Tricky virus

The Nimda worm used almost every trick in the book to infect computers and spread across the internet, exploiting the weaknesses of Microsoft Windows.

It rolled together many of the techniques used by other viruses, including raiding e-mail address books to attack both individual computers and web servers.

Virus top 10

Nimda

Sircam

Magistr

Hybris

Apology

VBSWG-X

Kakworm

SST-A

BadTrans

Navidad

Source: Sophos

The second most prevalent virus was Sircam, a worm which plundered address books for new places to send itself.

But one of the most hyped viruses of the year, Code Red, did not even make it into the Sophos top 10.

The virus, which hit the headlines in July, failed to do as much damage as some had predicted.

Sophos has detected 11,160 new viruses and worms so far this year, such as Anna Kournikova and Homepage.

It expects more viruses to come in 2002, especially so-called e-mail-aware worms. These types of viruses contain their own mail program so they can spread with no external help.

The company also warned about the emergence of viruses that attack instant messaging programs, calling for increased vigilance from home users and businesses in the light of these new dangers.

Mr Cluley said the typical virus writer was male, aged 14 to 24.

"There're 70,000 viruses in existence, we've got enough, we don't need any more," he told BBC Radio 5Live.