The MyDoom computer virus, now rated the second-worst email worm in history, hit the internet yesterday, choking the website of its victim, the SCO Group software company.
Microsoft - the other target of the virus writer, appeared to be unaffected. However, as the full weight of the attack was expected to hit about 3am Melbourne time today, it will only be known this morning if Microsoft has escaped unscathed.
The worm is believed to have infected up to 500,000 computers around the world, causing each to fire off emails at the rate of three every second to the SCO and Microsoft websites.
The barrage of denial-of-service "bombs" is expected to continue for up to 12 days.
The website of SCO, based in Utah, was off the air for most of yesterday. But SCO spokesman Blake Stowell said the disruption was due to internet service providers who had blocked access to SCO, believing they could limit exposure to the virus that way.
The virus is set to follow the sun, triggering its barrage in a rolling attack across the time zones of Europe, Asia and the US, as the clock inside each infected computer ticks past midnight into February 1.
An estimated 10,000 infected computers in Australia, most in homes and small businesses with inadequate anti-virus software, were among the first to release MyDoom's torrent of emails yesterday.
MyDoom surfaced a week ago and has become the fastest spreading and second most-costly virus ever, behind SoBig, which struck in August last year and is estimated to have caused a $US37 billion ($A48.5 billion) loss in productivity.
MyDoom invaded computers when users were tricked into opening an attachment to a message purporting to come from their internet service provider.
One Australian company reported 1000 MyDoom-generated emails hitting its firewall every minute on Friday. The McAfee AVERT anti-virus research centre in Sydney estimated one in 10 emails over the weekend was carrying MyDoom.
Microsoft and SCO are offering a reward of $US500,000 for information leading to the arrest of MyDoom's author.
Russian internet security firm Kaspersky Labs said it had traced the first emails infected with MyDoom to Russian internet service providers. "But it could (just as easily) be an attempt to mislead us," a spokesman said.
Anti-virus experts yesterday warned that many Australian home and small business computers may be infected by a similar virus called MiMail. They advise users to install anti-virus software, available on the net, some of it free, before opening email attachments, even from people they know.
Website paralysed as MyDoom barrage begins
By Garry Barker
February 2, 2004