-- card: 26991 from stack: in
-- bmap block id: 0
-- flags: 0000
-- background id: 2783
-- name: MDEF Virus


-- part contents for background part 10
----- text -----
MDEF Virus

-- part contents for background part 12
----- text -----
Macintosh Viruses
MDEF Virus Resources
MDEF Virus Operation
MDEF Virus Removal


-- part contents for background part 2
----- text -----
   The MDEF Virus (also called the Garfield Virus), discovered in mid-1990, is similar in concept, but not in execution, to the WDEF Virus.  Where the WDEF Virus replaces the standard Window DEFinition routines used by the Finder to draw windows, the MDEF Virus replaces the Menu DEFinition routines used by all programs to draw menus.
   However on the newest Macs (the IIci and the IIfx), the Menu Definition is in ROM and cannot be overridden by the virus.  Therefore, on these systems (and possibly the Portable) this virus can only infect the System file and cannot spread from there to other applications.
   A second strain of this Virus, MDEF B, differs from the first in that it bypasses CE Software’s Vaccine INIT.

-- part contents for background part 11
----- text -----
   It has also been determined that with certain machines running specific System software (eg. Mac IIci with System 6.0.5), the virus cannot spread at all.
   It is believed that after a period of time, or a certain set of actions (not known at this time) the virus will remove its Menu Definition causing the menus to stop functioning.