Early birds catch Davinia worm

But get your MS Office patch now

Even though the 'Davinia' worm has done far less damage than was first feared, anti-virus experts warn it exploits a vulnerability in Microsoft Office that most users have left open.

And the techniques used to write the Davinia worm could be used by virus writers to wreak far more damage.

According to the Virus boffins at Kaspersky Labs in Russia, Davinia has a very destructive payload, wiping the hard drive of any infected machine. However, it seems to have been defeated by its rather ponderous method of propagation. Antivirus companies are reporting that few of their customers have fallen victim to the virus - described as potentially another Love Bug by its discoverer, Panda Software.

A target computer is sent an email containing two script programs. The first opens an Internet Explorer browser window and initiates a link to the virus writers' site and the second opens a Word document from the site.

The Word document contains a macro that switches off built-in anti-virus protection, exploiting the "Office 2000 UA Control Vulnerability", discovered in May 2000 and for which a patch is available from Microsoft.

Then it emails a link to the vandal's Web site to all contacts in the victim's Outlook address book.

Kaspersky Labs says the rogue site is the only place where the virus part of the worm exists. This site has now been shut down.

However, other virus writers could use the same trick to propagate new malicious code, so the Russian virus hunters recommend that people download the patch for the vulnerability here.

Graham Cluley, senior technology consultant at anti-virus vendor Sophos, said that many, if not most users, have so far failed to apply the MS Office patch. This is important because the vulnerability means a virus could be developed that infect users without them opening an attachment in an email message.

Cluley criticised Panda Software, which discovered Davinia, for exaggerating the impact of the worm, and for its tardiness in exchanging copies of the malicious code through the Rapid Exchange for Virus Samples group, an industry group. ®

Lucy Sherriff contributed to this story

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