Viruses Are Riding On Spam, MessageLabs Says

By Internetweek.com , InternetWeek
Aug 1, 2003 (6:00 AM)
URL: http://www.internetweek.com/story/showArticle.jhtml?articleID=12807951

Techniques used by spammers to send unwanted advertising to people's e-mail boxes are also being used to send viruses that are often being altered and re-sent to fool anti-virus software, an e-mail security company said Thursday.
The trend identified by MessageLabs is part of the ongoing convergence between viruses and spam. Officials with the New York-based company said spam messages containing backdoor-trojan attachments are being sent in large volumes. The attached trojans are being altered and redeployed, almost on a daily basis, to outsmart signature-based, anti-virus software.

In the past, backdoor-trojans were typically sent by virus makers and distributed through some of the sophisticated mass-mailing techniques contained within viruses themselves, Mark Sunner, chief technology officer of MessageLabs, said in a statement. Recently, we have started tracking a growing convergence between the techniques of the virus makers and spammers. It is becoming clear that spammers are now adopting aggressive, determined techniques to sustain their ability to spam and outsmart some of the outdated solutions being used to fight them.

Once they have entered a company's network, the backdoor-trojans can be used maliciously in many ways. In particular, they can be used to create an open-proxy whereby the compromised computer can be used to surreptitiously send millions of new spam messages, MessageLabs said.

Companies' most vulnerable attacks are those that rely upon signature-based, anti-virus software, which has to be updated constantly across a new in order to keep pace with the deluge of new variants of these spam-based trojans.

MessageLabs also said that in July, it stopped 79.7 million spam messages, or 1 out of every 2 e-mails sent by its corporate customers. That number was 10 million more than the total number of spam messages stopped in all of 2002 by the company.