This virus is probably written by the same author as the PSQR variant of the Jerusalem virus, as it checks if that virus is present, when it is run. This virus will overwrite the last 32 bytes of any file it infects, possibly destroying the victim. Prudents activates on May 1st - May 4th of any year, interfering with disk writes.
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.