Threat Description



Category: Malware
Platform: W32
Aliases: CMD640X, Trojan.Cmd640x


During early 1995, many PC users were confronted with a mystical "Pox on you" -message which appears on the computer's display when the machine was booted. When the matter was examined, the message was traced to an IDE driver file called CMD640X.SYS. The file comes with CMD PCI IDE drivers.

The message is not caused by a virus, nor has the original program file been tampered in any way. Rather, it seems that the driver's programmer has added a Trojan Horse routine to CMD640X.SYS as a "joke".

CMD640X.SYS activates randomly. It keeps printing the following message on the screen for a while, after which it crashes the computer.

     A poX oN yOu!! yoU wiLl bUrN iN tHe fiReS of HeLl!! A poX         oN yOu!! yoU wiLl bUrN iN tHe fiReS of HeLl!! A poX oN         yOu!! yoU wiLl bUrN iN tHe fiReS of HeLl!!  

The only way to eliminate this nuisance is to install a sanitized version of the CMD driver into the computer.


Automatic action

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

More scanning & removal options

More information on scanning or removal options is available in the documentation for your F-Secure security product on the Downloads section of our Home - Global site.

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

Contact Support

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

Description Details: Mikko Hypponen, F-Secure


Suspect a file or URL was wrongly detected? Submit a sample to our Labs for analysis

Submit Now

Give And Get Advice

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

Learn More