This group of viruses is derived from the Jerusalem virus, but they have been significantly modified. They are longer, 2576, 2900, 3004, 3012 and four 4096 byte variants. Two of the 4096 byte variants are also known as "Invader". The 4096-byte variants also contain code for infecting the boot sector. The reason the viruses are also known as AntiCAD is thet they are targeted against the AutoCAD program. When a program named ACAD.EXE is run or sometimes when Ctrl-Alt-Del is pressed, the virus will activate, overwriting data on floppy disks and hard disks, as well as garbling the contents of the CMOS.
See also Jerusalem.