Malware authors are using Skype to help spread a pair of Trojan packages.

The malware does not exploit flaws in Skype as such, as a computer worm might do, but spreads by tricking users into agreeing to run hostile code, which poses as a "cool program" from one of their contacts.

F-Secure reports that two different and separate malware samples are using Skype as an attack vector. One malware sample - called "sp.exe" - attempts to link to a site called nsdf.no-ip.biz to download additional malware components. The other sample of malware, first detected at the beginning of October, attempts to download components from marx2.altervista.org.

The websites used to download secondary malware samples have both been pulled since the attack was detected earlier this week.

Although the immediate threats posed by these Skype Trojan attacks is therefore minimal, the assault serves to illustrate the changing attack vectors (in this case a VoIP client) that hackers are turning to as an alternative to the well-known risks of malware in email or harboured on maliciously-constructed websites. ®