Twelve Tricks is a
Trojan horse that first appeared around 1990.
Purdue University issued a bulletin about the Trojan on March 8, 1990.
The Twelve Tricks Trojan Horse
/ref> The Trojan came in an altered utility file called CORETEST.COM, which was intended to test performance of hard drives. It affected IBM platform
IBM PC compatible computers are similar to the original IBM PC, XT, and AT, all from computer giant IBM, that are able to use the same software and expansion cards. Such computers were referred to as PC clones, IBM clones or IBM PC clones. ...
computers running MS-DOS or PC DOS. The Trojan alters the master boot record
A master boot record (MBR) is a special type of boot sector at the very beginning of partitioned computer mass storage devices like fixed disks or removable drives intended for use with IBM PC-compatible systems and beyond. The concept of MBR ...
(partition sector) and, at every reboot, it installs one of twelve "tricks" that causes issues with hardware or operation of the computer. The trick vanishes when the power is cut off, and any of the twelve tricks may appear or reappear on the next reboot. In addition, on each boot the Trojan uses a random number generator to determine whether to do a low-level format
Format may refer to:
Printing and visual media
* Text formatting, the typesetting of text elements
* Paper formats, or paper size standards
* Newspaper format, the size of the paper page
Computing
* File format, particular way that informatio ...
of the active copy of the boot sector and the first copy of the FAT; there is a 1/4096 chance of this happening. If the format does not happen, the Trojan randomly changes one random word in any of the first sixteen sectors of the FAT, leading to a gradual corruption of the file system.
References
External links
* ''Morality and Machines'
214
Trojan horses
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