[comp.virus] LaserWriter viruses

forags@violet.berkeley.edu (08/12/89)

Networked Apple Laserwriters aren't really subject to permanent virus
infestation, since a power-off cycle will clear their RAM.

HOWEVER, a proficient Postscript programmer can deposit code in an LW's
memory which can stay resident and affect other users' output until the
power is cycled.  These modifications can include re-defining standard
Postscript operators to do different things (such as "showpage" could
be extended to overprint the word "CLASSIFIED" on every page printed).

PostScript has a password mechanism to prevent some alterations to persistent
parameters (such as printing a start-up page), but many users leave the
password un-set.

Al Stangenberger                    Dept. of Forestry & Resource Mgt.
forags@violet.berkeley.edu          145 Mulford Hall - Univ. of Calif.
uucp:  ucbvax!ucbviolet!forags      Berkeley, CA  94720
BITNET: FORAGS AT UCBVIOLE          (415) 642-4424