Such viruses are grouped in the following families:
- Non-resident viruses, which infect only COM files SillyE
- Non-resident viruses, which infect only EXE files SillyCE
- Non-resident viruses, which infect both types of files SillyCR
- Resident viruses, which infect only COM files SillyER
- Resident viruses, which infect only EXE files SillyCER - Resident viruses, which infect both types of files SillyOR
- Resident viruses, which overwrite the host files
The variants in each family are named by their infective length.
it might be a good idea to search all files for infection, as some members of SillyOR family will corrupt data files by overwriting them with their own code. F-Secure anti-virus products are able to locate these corrupted data files so you can replace them with good copies.
This virus infects COM files and EXE files with COM extension. It doesn't check the host file size before infection so it can corrupt large COM files. It marks infected files by adding 100 years to the file date and setting the second fields to 62.
The virus has no texts or activation routine.
This virus was reported to be in the wild in Hungary in January 1996.