The code inside a popular music playing program contains a bug that could allow computer viruses to be concealed within MP3 files.
Experts say this particular backdoor can easily be closed, but add that the flaw shows computer viruses could potentially exploit the huge popularity of internet music sharing.
The music player Winamp was found to contain the bug by Swedish computer engineer Andreas Sandblad. In an alert to a computer security mailing list, Sandblad explains how the bug could be used by a computer virus in order to spread.
Sandblad writes: “The virus is activated when the MP3 file is played in Winamp and can then infect other MP3 files found on a hard drive or network.” The bug exists in the way the player reads the part of MP3 files used to identify artist, title and genre, he says. By modifying this section of an MP3 file, a target computer can be made to perform unauthorised tasks.
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Sidestepping the problem
However, the latest release of the program, version 2.80, does not contain the same flaw, and the problem can also be sidestepped by deactivating Winamps “minibrowser”, which is used to look up information on the web.
Graham Cluley, head of research at Sophos Antivirus, says the hole would be tricky to exploit and does not pose a major threat. “It’s interesting – but it’s not a reason to be more wary of MP3’s,” he says. But he warns that viruses designed to hide in MP3 files could be seen more in the future: “It’s just evidence that virus writers are looking for new vulnerabilities.”
The Winamp player has been downloaded over 20 million times, according to the download website CNet. MP3 music sharing has exploded in popularity with the spread of peer-to-peer file sharing applications, such as Napster and its successors.
