Whilst working out methods of cracking Skype calls has been a popular hacker pastime for some time, the Peskyspy trojan - which surfaced in late August - hit the headlines as it opened a back door into a user's PC and, by using a process of bypassing firewall protections, effectively allowed remote access to the Skype data stream.

Although Symantec and Trend Micro - which calls the malware Spytap - have both rated the trojan as low risk, Skype has released v4.1 of its internet telephony and instant messaging client.

In a blog posting of late last week, Skype said that v4.1 counters any problems that Peskyspy trojan poses, as well as reducing spam, by ensuring that links are not clickable in contact authorisation requests.

"The new release is a bugfix release which resolves many of the problems you have been telling us about", said the blog posting.

"We recommend everyone to update to this build now."

In another blog posting, Skype noted that the Peskyspy trojan does not compromise Skype, but the PC on which it runs.

Once loaded, the Peskyspy trojan monitors the audio data stream between the PC hardware and the Skype application - which Skype likens to listening in on a conversation by standing next to the person speaking.

Skype has advised users of its software to adhere to previously issued best practice advice and not to open files sent by people they do not know, as well as keeping IT security software updated on a regular basis.