Authors behind the Storm worm have switched tactics yet again.
In the latest twist to the ongoing saga, emails punting the malware now contain fake links to YouTube. In reality the links direct potential victims to a malware loaded website designed to turn vulnerable boxes into spam-spewing zombie clients.
According to net content security firm Marshal, the latest Storm spam campaign uses humorous, familiar comments alongside fake YouTube links to lull recipients into believing they have been forwarded a link to a funny or outrageous video. Examples of the email text include 'dude don't send that stuff to my home email...', 'LMAO, your crazy man,' and 'OMG what are you thinking.'
"To most users the links will appear legitimate, as though they connect directly to the YouTube website...The spammers are using a simple email/HTML authoring trick to make the link appear to go to one place, but it actually goes to a completely different location," explained Bradley Anstis, director of product management at Marshal.
"The obfuscated Web link sends the user to a false website that appears to be part of YouTube, featuring YouTube logos and legitimate-looking text. The website attempts to exploit vulnerabilities in the visitor's browser to automatically download malicious files. If it fails to successfully exploit the browser, the site encourages the visitor to manually download a file called 'video.exe' which is the Trojan," he added.
Malicious email punting the malware scam accounted for between between 4 and 6 per cent of all email spam traffic sent since Monday, according to Marshall. The unidentified bot herders behind the campaign are experts at using social engineering to extend their army of botnet clients.
The malware strain first surfaced in January in emails attempting to trick users into visiting maliciously constructed websites under the guise of messages promising recipients information about the storms ravaging Europe at the time.
In the last two weeks the crackers have further refined their tactics, including attempts to trick users into visiting maliciously constructed websites via login confirmation spam.
"This YouTube spam attack comes less than a week after the confirmation spam campaign. This group is definitely escalating its activity," Anstis added. ®