F-Secure Virus Descriptions : Jihuu.621

NAME:	Jihuu.621
ALIAS:	621
ORIGIN:	Finland
SIZE:	658
TYPE:	Resident COM-files
REPAIR:	Yes

This virus activates on Friday the 13th displaying the message:

        "Something wonderful has happened, your PC is alive".

When it is on the 4th day of any month it shows the message:

        "Water detected in match-co-processor".

Jihuu will activate in the year 2000. Then it tries to overwrite the hard disk and displays:

        "PARITY ERROR System halted".

VARIANT: Jihuu.686

SIZE: 686

This variant was found almost three years after the variant 621 - in May 1994. The operation of the virus is identical, but the text messages have been encrypted with XOR FFh operation.

[Analysis: Mikko Hypponen, F-Secure]