When the virus is loaded into memory, it hooks INT 13h, 14h, 21h to infect any DOS executable that is run by writing itself to the beginning of the file, excluding COMMAND.COM. It also deletes the CHKLIST.CPS file.
Depending on the system time, the virus deletes the files having the extension of DAT, or disables printing. Depending on its internal counters the virus disables Create/Delete Directory and Set Time/Date DOS-functions, slows down PC, erases disk sectors.
The virus contains the text strings, the last one is encrypted :
.dat chklist.cps COMMAND * THE FOUR SEASONS VIRUS * (C) WET, PARIS 1991 * I HAD MUCH FUN WRITING THIS VIRUS, I HOPE YOU HAVE FUN WITH IT TOO!! * MES AMITIES A PATRICIA M., JE T'EMBRASSE TRES FORT ET JE PENSE A TOI *