Attack of the killer e-worms

By RICHARD WOOD

Like something out of a horror movie, the internet has suffered a deluge of computer worms and viruses clogging traffic.

Over the past week, three significant worms or viruses have been active, the latest being the Sobig. F virus.

Antivirus firms estimated this week that 700,000 computers had been affected by the MSBlast worm, which was designed to launch a traffic attack on a Microsoft server.

Microsoft said more than 80 million security patches had been downloaded and the name of the server had been changed to avoid the attack.

But hot on its heals a variant of MSBlast known as Nachi targeted both the same PC weakness and another security hole as well.

Nachi is more aggressive than MSBlast and also tries to download the security patch for MSBlast, creating a "do-good" impression.

Nachi was the big menace to traffic on Tuesday and Wednesday, and is likely to have exceeded MSBlast by now.

Greg Cross, chief executive of local network analysis firm Esphion, whose customers include some of the country's biggest internet providers, said Nachi traffic was doubling every day.

Esphion first spotted the extra traffic caused by Nachi on Monday evening.

Cross also confirmed the rapid acceleration of the Sobig. F email virus since Tuesday.

At last count it was neck-and-neck with Nachi in terms of internet traffic impact.

Sobig picks addresses off an infected computer and pretends to be sending from those addresses.

An overseas report noted that at one point the virus was generating one in every 17 emails.

A Telecom Xtra spokeswoman also reported Sobig. F as the fastest mover and said it had caused a 10 per cent increase in mail volume from Tuesday to Thursday.

The virus accounted for 95 per cent of a 10-fold increase in the number of bugs caught in Xtra's antivirus email filter over that period.

While MSBlaster crashes PCs and sets them up to attack Microsoft, Sobig opens a "back door" for hackers to enter and take over a PC system.

Microsoft recommends that the public use firewalls and antivirus software along with signing up for its Windows Update service, which automatically advises of security patch updates.