All but the first 52 bytes and last byte of the virus are encrypted with a sliding XOR algorithm. The XOR encryption key is incremented after each byte is processed. The seed value is incremented with each new generation of the virus.
If it happens to be the 11th November when the infected program is run, or if the encryption seed is AEh, the beginning of the current program file is overwritten by a 194 byte long program. When this program is run, it just prints the following text and terminates:
FLOWER Support the power of women Use the power of man Support the flower of woman Use the word FUCK The word is love Originally released 7 April '92
After writing the infected program to disk, the virus restores the files date/time field and attributes.
Normally, when the infected file is run, a dummy critical error handler is installed during the infection stage and the virus tries to infect one EXE file in the current directory and one EXE file in the subdirectories of the root directory.
Files which are hidden or read-only are not infected. The file attribute is cleared and restored afterwards if infection did not succeed. On successful infection only the archive bit is restored, and the hidden and read-only attributes are set so as to prevent multiple infection. Infection is done by rounding up the length of the file to the next paragraph and appending.
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.