New worm spreading via Skype

Multilingual malware posing as porn in chat messages.

VoIP and chat system

Skype

has been targeted by another worm, sending chat messages to harvested contacts posing as links to pornographic images, which in fact download and install copies of the worm. The new malware has been variously dubbed ‘Pykspa.D’, ‘Skipi.A’, ‘Ramex.a’ and ‘Pykse.b’.

The fake messages, which are as likely to come from known contacts as from strangers, can contain text in a wide range of languages selected by the worm based on the sender’s system locale settings, which hint that the linked erotic images may be of interest to the recipient. Following the link brings up a ‘soap bubble’ screensaver, and installs the worm.

Once a system is infected, the worm attempts to disable a range of security software, and adjusts the

Windows

hosts file to prevent access to security updates and advice. It harvests further addresses from the local contacts list and continues spreading itself across the

Skype

network.

The worm, a variant of a previous

Skype

worm

seen in April

, is currently thought to be spreading at fairly low levels, and requires user interaction to accept and run the malware. Users are reminded to exercise caution online and to ignore unsolicited messages containing suspect links.

A

Skype

blog posting with initial details, including manual removal instructions, is

here

. Further discussion on the

Symantec

blog is

here

, with detailed analysis of the malware

here

.

Posted on 11 September 2007 by

Virus Bulletin