Threat Description



Aliases: VB.ab, Virus.Win32.VB.ab
Category: Malware
Type: Virus
Platform: W32


This malware copies itself to different folders of a local hard drive with different names.


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.


Detailed instructions for F-Secure security products are available in the documentation found in the Downloads section of our Home - Global site.

You may also refer to the Knowledge Base on the F-Secure Community site for further assistance.

Technical Details

When the malware's file is run, it first shows a fake error messagebox:

The text in the messagebox can also be:

File not found windll.dll missing Unknown format   

Then the virus scans all local hard drives and copies itself with different names to different directories on it. The virus "borrows" names of files located in a folder where it copies itself to, but in order not to overwrite these files, the virus changes its file name a bit - it adds one extra character to the beginning of its file name. For example if a virus finds a file named NDD.EXE in a folder, it will copy itself as PNDD.EXE or SNDD.EXE and so on. On the screenshot the malware's files are in red squares:

If the virus finds a JPG, AVI or MP3 file, it creates a copy of itself by "borrowing" a name of that file and adding .EXE extension. For example for CLOCK.AVI the virus will create a file named CLICK.AVI.EXE. This malware creates only one file in each folder each time it is run.


VB.ab is detected with the following F-Secure Anti-Virus updates:

Detection Type: PC
Database: 2006-01-04_05

Description Details: Alexey Podrezov, January 13, 2006


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