MessageLabs has warned that spammers are already modifying their tactics when it comes to the emerging trend of using audio rather than text attachments in unsolicited mail.
In a statement, MessageLabs claimed that, following the first spam campaign involving audio files on 17 October 2007, which attempted to control the value of stock for “nefarious reasons”, spammers are now moving on from simply attaching audio to mail to linking through to content hosted on multimedia sites such as YouTube.
“This recent trend proves that spamming techniques are becoming more innovative,” said MessageLabs in its statement. “As image spam shifts from email attachments to images on free image-hosting sites, [we] believe that it is only a matter of time before the spammers apply the same approach to audio spam and upload the message to free multimedia-hosting sites such as YouTube, Google Video and MySpace.”
Spammers used attached MP3 music files to try to “sneak messages past spam filters”, said MessageLabs. The spam run of 15 million emails lasted 36 hours and used Storm worm-infected computers for the purposes of dissemination, MessageLabs said.
The MP3 file names were music-related, including files called “beatles.mp3″, “britney.mp3″ and “elvis.mp3″. They contained a poor-quality, 25-second voice track promoting a stock offering from Exit Only Incorporated for its Text4Cars.com website. The spam did not contain any detected malicious code.