According the the Symantic press release
http://www.prwire.com.au/pr/14463/symantec-threat-bulletin-trojan-peskyspy-recording-skype-voip-conversation
"The Trojan is detected by Symantec as Trojan.Peskyspy and can be downloaded to a computer by way of tricking the user with an E-mail scam or other social engineering tactic.
...
The Trojan is targeting Windows API hooks, a technique used to alter the planned behavior of an application, that Microsoft has intended to be used by audio applications. The Trojan compromises the machine and then through the hooking technique is able to eavesdrop on a conversation before it even reaches Skype, or any other audio application."
So tell all windows users DO NOT OPEN unsolicited email. Beware of social engineering tactics, and before opening a file even from a friend, find out if they sent it to you on purpose.
Doing that the windows machines should be safe... for the time being.
Earlier this week, Swiss programmer Ruben Unteregger who has been reportedly working for a Swiss company ERA IT Solutions responsible for coding government sponsored spyware, has released the source code of a trojan horse that injects code into the Skype process in order to convert the incoming and outgoing voice data into an encrypted MP3 available at the disposal of the attacker.
Here’s how the trojan, currently detected as Trojan.Peskyspy, works:
“When the Trojan is executed, it injects a thread into the Skype process and hooks a number of API calls, allowing it to intercept all PCM audio data going between the Skype process and underlying audio devices. Note: Since the Trojan listens to the data coming to and from the audio devices, it gathers the audio independently of any application-specific protocols or encryption applied by Skype when it passes voice data at the network level.
Note: The incoming and outgoing audio data are stored in separate .mp3 files. The Trojan also opens a back door on the compromised computer, allowing an attacker to perform the following actions:
- Send the .mp3 to a predetermined location
- Download an updated version
- Delete the Trojan from the compromised computer”
Skype is often dubbed a “national security threat” by governments all across the globe due to their — at least publicly acknowledged — inability to crack the 256-bit encryption VoIP calls.
And while some of these governments are reportedly spending surreal amounts of tax payer’s money (Rental of the Skype-Capture-Unit per month and instance EUR 3.500) in order to achieve their objectives, others are taking the cost-effectiveness path by attacking the weakest link in the process - the end user infected with a targeted DIY government sponsored spyware recording all ongoing and incoming Skype calls, thereby bypassing the need to attack the encryption algorithm.
