Category: Malware

Type: Virus

Aliases: Prague, Backtime


This virus was found in August 1991. It contains the texts 'Backtime' and turns the system timer to work backwards.


Automatic action

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Technical Details


Slightly shorter, only 512 bytes. Displays the following error messages occasionally:

Bad command
error reading device CON

Bad command
error writing device CON


This variant is also 512 bytes, but it produces a very interesting "shaking" effect on the screen, when run, as the virus interferes with the video controller. This version contains the text "Shaker"

Variant:Pizza (Plastic Pizza)

This 1236 bytes long variant carries a copy of the Michelangelo virus with itself, and will infect all clean hard drives it spots with it.