Security giant Symantec claims to have found the public release of source code for a Trojan that targets Skype users.

Trojan.Peskyspy is spyware which records a voice call and stores it as an MP3 file for later transmission.

An infected machine will use the software that handles audio processing within a computer and save the call data as an MP3. The file is then sent over the internet to a predefined server where the attacker can listen to the recorded conversations.

Since the call is an MP3 it does not take up too much space, and means that transfer speeds are lower.

Symantec admits that the threat risk is low at the moment but that, since the code is publicly available, malware authors are likely to use it as part of a customised snooping package.

The downside for the malware creators is that they would need a lot of time on their hands to go through hours of Skype audio files to find anything of monetary interest.