Trojan:SymbOS/Skulls.J
Summary
Skulls.J is minor variant of Skulls.D trojan. The main difference between Skulls.J and Skulls.D is that the Skulls.J doesn't drop any cabir variants directly. The Skulls.J drops SymbOS/AppDisabler.A trojan, which drops Cabir.Y and Locknut.B on the device.
Removal
Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.
A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:
-
Check for the latest database updates
First check if your F-Secure security program is using the latest updates, then try scanning the file again.
-
Submit a sample
After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.
Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.
-
Exclude a file from further scanning
If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.
Note: You need administrative rights to change the settings.
Technical Details
In addition of dropping the AppDisabler.A the Skulls.J tries to disable F-Secure Anti-Virus and other Anti-Virus applications.
F-Secure Anti-Virus protected from the trojan attack as it is capable of detecting the trojan using generic detection, which was created long before this trojan surfaced.
Spreading in: Skulls.J trojan SIS file has been manually inserted into several different pirate copied games and applications. However none of these files have been detected in the wild.
Payload
Tries to disable Anti-Virus and drops SymbOS/Appdisabler.A.
Skulls.J also contains application that displays animation of flashing skull picture. But unlike in Skulls.D, Skulls.J does not contain startup code for the animation, this code is introduced by AppDisabler.A, but is prevented from working by Locknut.B which is also dropped by Appdisabler.A.
