Worm:Win32/Koobface.gen!A is a generic detection for a worm spreads when a user logs into their profile account on the Internet social network sites 'MySpace', 'Facebook' and others.
If this worm is executed, Win32/Koobface copies itself to the Windows folder as in the following examples:
The worm may drop a cleanup Batch script file also having a random file name to the root of the local drive, as in this example:
The worm may execute the cleanup batch script to remove the originally executed worm and to remove itself. The registry is modified to execute the dropped worm copy at each Windows start.
Adds value: systray
With data: "%windir%/<worm file name>"
To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Depending on the variant, other values are created instead such as "sysftray2" or "sysldtray".
MySpace and FaceBook Contacts
Win32/Koobface searches in the default Internet Explorer cookies folder for browser cookies related to the Internet social network sites including the following:
In some variants of Win32/Koobface, if the worm determines that none of these sites are visited, the worm may delete itself and may display following message box:
In the wild, the worm may connect to the Web site 'zzzping.com' to download and execute malware.
The worm spreads by sending messages containing a hyperlink to a copy of worm to friends or contacts of the infected user. Friends that receive the message may visit the link to download the worm and repeat the cycle of spreading to others.
Removes Audible Navigation Alerts
Some variants of Win32/Koobface may delete a registry subkey that references navigation sounds such as the 'click' sound when navigating from one Web site to another. The following subkey may be deleted by the worm:
Analysis by Vitaly Zaytsev