This is a typical boot sector virus. It sometimes displays a 'Runtime error' message.
Defo was reported to be in the wild in several countries during summer 1996.
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.
Description Details: Mikko Hypponen, F-Secure