Swiss government is working with local ISP to plant spyware, aka Superintendent Trojan to target PC directly and monitor the "victim" voice input.

Instead of capturing the voice data packet, Swiss government will ignore the encrypted data packet and plant the spyware via the target PC's ISP. The spyware is a trojan which can record all the voice input from the microphone, encrypt it and send to a designated server. Swiss security company ERA IT Solutions has made an unknown Trojan. The trojan will not be detected by major security scanner since it is only used by limited agencies.

Other than monitoring your VoIP calls like Skype, the trojan will be able to activate your microphone at anytime to start recording. Depends on the setting, the trojan will self destruct and leave no trace.

heise-security via theregister