If your computer is infected:

We recommend you disconnect from the Net as soon as possible and have your machine cleaned out. Once clean, you should advise everyone in your address book of your problem so that they can fix the problem themselves if they've been silly enough to open an attachment from you containing the virus. If you know who sent the virus, copy the contents of this message and send it to them in turn.

Avoiding future infections:

• We suggest you get rid of Microsoft Outlook if you are using it, in favour of Eudora or Navigator/Messenger. Most virus writers target Outlook because it's full of security holes. (It uses Explorer for display of attachments!). Typical Microsoft bloatware.
• Whatever your mail software, configure it NOT to open attachments automatically by default.
• Invest in a good virus scanning software system.
• If you receive any attachment of type PIF, SCR, DOC, EXE, VBS etc, always virus scan it before opening it.
• If you receive any emails alerting you to a new virus and exhorting you to send the warning to eveyone you know, DON'T DO IT. It is almost certainly a hoax. Visit www.symantec.com and check with their hoax register. If it was a hoax, tell the person who sent it to you to alert other folks up and down the chain not to forward it any further.

If all ISP's scanned e-mail as it arrived on thier servers, and simply deleted anything with a known worm or virus in it, most of the threat to users would disappear overnight.  Even if only your ISP did it, you'd sleep a lot better at night!

Unfortunately ISP's have a vested interest in the status quo as it increases download volumes and their own profits.

Lobby your Internet Service Provider to provide server-side virus scanning and neutralisation of incoming email.  Complain!!.

We use "Spamtrap" server side filtering to prefilter our emails.  It includes a virus filter.

Microsoft makes their dollars by selling software - lots of it.   In order to keep the dollars rolling in, they continually roll out new versions of existing programs with new whiz-bang features.   For many software companies, it would appear that getting new software to market is usually a much higher priority than making sure that the software is bulletproof or even particularly efficient - they rely on the addition performance of the newer computers to compensate for the huge bloat in software code.

Many of the virus/worm writers seem to be exploiting bugs in Microsoft software, in particular Microsoft Outlook and Explorer.  It seems to be a case of products that are too heavily featured for their own good.  Outlook is capable of using other Microsoft components to view and execute various attachments.  Unfortunately, the worm writers target this very ability.  A serious bug in Microsoft Internet Explorer 5 and below renders Outlook security useless for some recent viruses.

A similar bug exists in the Microsoft Office suite, nullifying the normal virus protection in the software. Micro$oft has patches for those products still "in service" but if you're happily working on a back level of the software, it will cost you for an upgrade.  Once again M$ profit from bugs in their products!

Various Virus/Worm bulletins

More about viruses

Symantec:
http://securityresponse.symantec.com