Threat description




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


Automatic action

Depending on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the suspect file, or ask you for a desired action.

More scanning & removal options

More information on the scanning and removal options available in your F-Secure product can be found in the Help Center.

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

Contact Support

F-Secure customers can request support online via the Request support or the Chat forms on our Home - Global site.

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

Submit a Sample

Suspect a file or URL was wrongly detected? Send it to our Labs for further analysis

Submit a Sample

Give And Get Advice

Give advice. Get advice. Share the knowledge on our free discussion forum.

More Info