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From: forags@violet.berkeley.edu
Newsgroups: comp.virus
Subject: Re: LaserWriter viruses
Message-ID: <0002.8908141126.AA08231@ge.sei.cmu.edu>
Date: 11 Aug 89 17:34:27 GMT
Sender: Virus Discussion List <VIRUS-L@IBM1.CC.Lehigh.EDU>
Lines: 17
Approved: krvw@sei.cmu.edu

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