This virus adds 1-16 extra bytes to programs before it infects them. If it infects a very small file, it can sometimes not be removed. Two variants, 789 and 801 bytes long are known. The virus activates on September 18th, after 7:00 AM, overwriting the hard disk.
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 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.
Probably an older variant - only able to infect EXE files.