Cleaner activates on the 8th of September on every year. At this date, the virus will display the following text on the screen:
O HDD-CLEANER Version 2.0 O O Copyright (c) 1997 (1st JAN) O O Made in Hungary, Sopron O
DESTRUCTION IN PROGRESS...
After this the virus overwrites the beginning of the hard drive. Only the first 16 sectors are overwritten, so recovery is possible.
Cleaner will also cause different compatibility problems. It was found
in the wild in June 1997, after the Hungarian Magazine CHIP accidentally
distributed it on their cover CD-ROM.
[Analysis: Mikko Hypponen, F-Secure]