Sophos issues new Trojan warning

Engineers at Sophos' global network of virus and spam analysis centers have detected samples of a new Trojan horse being circulated via e-mail.

The Troj/BagleDl-W Trojan horse appears to have been deliberately spammed to e-mail addresses around the world.

According to Sophos, e-mail with the malware typically contain message bodies saying "Info" or "Texte", and are accompanied by attachments with filenames that include Health_and_knowledge.zip, text_sms.zip, max.zip, Business.zip and The_new_price.zip.

When the attached file is launched, the Trojan horse tries to connect to a number of Web sites in order to download malicious codes into the user's machine, Sophos said.

"Trojan horses can turn off your anti-virus or firewall, opening you up to further attack by hackers or even old viruses that normally you would be protected against," said Graham Cluley, senior technology consultant for Sophos, in a media statement. "My advice is keep your anti-virus automatically updated and always be suspicious of unsolicited e-mail attachments."

Sophos advises companies to adopt an e-mail gateway policy which can protect against new e-mail threats, even before anti-virus updates are available.

The security company has received few reports of active infections, despite noting that the Troj/BagleD1-W is in "wide distribution".

This Trojan horse, Cluley said, aims to take advantage of many people's instinct to launch an attachment in their e-mail messages, despite having no idea what it could do to their computers, he said.

"More companies are waking up to the benefits of stopping executable code from entering their organization via e-mail," he said. "Users who want to install software on their computer should be receiving it from their IT department, not from friends at other companies, or potentially dangerous spam mailings."

Sophos' latest warning comes after a report last month, released by e-mail security vendor BlackSpider Technologies, which found that virus-laden e-mail had dropped from 2.01 percent of all e-mail in August, to 1.75 percent in September.