The security supplier's latest research indicates that MP3 files have now emerged as the most popular enablers of spam campaigns.
"The tool box of spam senders is constantly evolving, but MP3s are now the weapon of choice," said MessageLabs senior analyst Paul Wood. "People know they should not open emails from strangers, but entertainment is the best enticement."
Until recently, PDF files represented the best option for conducting spam campaigns. But as IT security experts become increasingly vigilant in their attempts to filter out these attempts to bypass security, criminals moved on to other media. "Until this year, most spam was text and HTML based, but now they are moving to more compelling media," Wood said.
On October 17, MessageLabs intercepted the first copies of an estimated 15 million e-mail spam run that lasted 36 hours. The audio file consisted of an automated British accented female voice urging people to invest in property shares from Exit Only Incorporated. "You would be surprised by how many people actually fall for a ruse like this," Wood said.
Most spam-enabling MP3 files have names such as Beatles.mp3, Britney.mp3 and Elvis.mp3, MessageLabs says. However, the shelf-life of this criminal tool is limited. "Once people cotton on to this, we expect the next wave of this crime to be tied up with Powerpoint files," Wood said.