This parasitic resident virus infects COM files being executed. The virus counts programs being executed on an infected system. When the counter exceeds 256 the virus makes the hard disk unbootable by placing an infinite loop to the MBR code.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
More information on 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.