It's official - the Melissa email virus infected 99% of anti-virus companies with wild enthusiasm. That was one long-time Internet user's view of the coverage last week of the email-borne virus that caused international headlines.
The basic facts about Melissa are:
It is a Microsoft Word macro virus, written in the VBA programming language supplied with Word and is spread as a Word document attached to an email.
When a user opens an infected email the virus copies itself to the PC and lowers the security settings in Word.
If the PC has the Microsoft Outlook email program, it reads the first 50 entries in the address book and mails itself out to those addresses.
The virus does not contain a damaging "payload" of its own. The problems it has caused have been indirect - swamping mail servers with its messages in sites where Word and Outlook are widely used - like, er Microsoft.
Computers that do not have Outlook can still be infected, but the mail-out will not happen.
Once a PC is infected, the virus can cross from the original document (a list of sex-related Internet sites) to other documents. These in turn become infectious and will be mailed out if the virus is triggered in a future recipient's machine, so be very careful about preparing confidential documents if your machine may be infected.
To protect against infection:
Update anti-virus measures on your computer and network.
Ask correspondents (as Computimes does) to send only plain-text email.
Set Word to warn before opening documents containing macros and always disable macros when opening emailed files.
Never set an email program to automatically open attached documents.
Use the free Word file viewer available from Microsoft to view attachments. This does not execute macros. For further information see:
www.ciac.org
www.cert.org
victoria.tc.ca/techrev/melissa.txt