SymbOS/Skulls.b is a trojan that is similar to its predecessor, SymbOS/Skulls.a. The most notable difference is that this variant drops the SymbOS/Cabir.b worm on the device.
This trojan is likely to be received as an installation package (SIS), for example ICONS.SIS.
When the package is installed, copies of various system applications and their corresponding information files are installed to C:. With many devices running Symbian OS, applications on C: take precedence over those in ROM, enabling this trojan to essentially disable those applications (somewhat akin to a companion virus infection).
The information files for the various applications have been modified such that the application icons are all the default icon (compares to the skull and crossbone image that was used in the a variant of this trojan).
More information can be found at McAfee page.
11/30: SymbOS/Skulls-B is a Trojan
