hagins@gamecock.rtp.dg.com (Jody Hagins) (01/30/91)
Please forgive my ignorance on this subject... Is it possible for a virus, etc to cripple physical hardware components? I ask as I have recently experienced an abrupt halt of my system, frying my power supply. This occurred after aquiring a piece of software from a supposedly very reliable source. Just wondering if this is related, or a coincidence. Thanks for any help! Jody Hagins hagins@gamecock.rtp.dg.com Data General Corp. 62 Alexander Dr. RTP, N.C. 27709 (919) 248-6035 Nothing I ever say reflects the opinions of DGC.
n8541751@unicorn.cc.wwu.edu (Where there is darkness, light) (02/06/91)
hagins@gamecock.rtp.dg.com (Jody Hagins) writes: >Please forgive my ignorance on this subject... >Is it possible for a virus, etc to cripple physical hardware >components? I ask as I have recently experienced an abrupt halt of my >system, frying my power supply. This occurred after aquiring a piece >of software from a supposedly very reliable source. Just wondering if >this is related, or a coincidence. >Thanks for any help! I have a book on assembly language programming of the PC video hardware which includes a caution against certain programming mistakes to avoid when setting up the video controller. It claims that you can actually physically damage a monitor from within software. Needless to say I haven't tried it to see if it's really true. I don't know about other components. Kris. - -- Kriston M. Bruland | . . . . . . . . . . n8541751@unicorn.cc.wwu.edu | . . . . . . . . . 8541751@nessie.cc.wwu.edu | . . . . . .
lan@bucsf.bu.edu (Larry Nathanson) (02/07/91)
While the existance of the HCF assembly command (Halt and Catch Fire)
has been debated, :-) I seem to remember a discussion similar to this.
I believe the basic conclusion was that it is impossible to damage the
CPU itself through programming.
However, peripherals remain very vulnerable- if you take a standard
hard drive, and drag the R/W head across the media 4 or 5 thousand
times, it can't be good. While it is unlikely that any user would
allow the machine to sit there grinding for several hours, it is
possible to write to virus to add 2 or 3 full head sweeps to each disk
access. This would slightly slow up the response time of the drive,
and might make it wear out much faster.
I saw a computer anecdote about some guys who had access to a printer
where imprints of the letters were layed out sequentially along a
linked chain. The chain spun laterally in front of 80 hammers, which
would strike, when the right character was in the right position.
These fellows found out the sequence of the letters, and attempted to
send that string to this printer to see what would happen. They said
that there were finding parts of the printer in the corners for many
months.
If one were to come up with a well sequenced access drive request,
timed with the drive speed, and in sync with the sector interleave, a
similar effect might be possible. However, as in the story, much
advance knowledge about the hardware is necessary. Unless the
hardware configuration is VERY public, it would almost have to be an
inside job. Writing enough code to screw with every HD, and every
printer around would make the virus big enough to be easily detected.
I think there may be ways to screw with the refresh rate of certain
brand monitors, but again- that requires inside knowledge- then there
is no reason to use viral propagation- a trojan horse will do fine.
- --Larry
- --
// Larry Nathanson . 726 Comm Av #5J . Boston, MA 02215 . 617 266 7419 \\
I've heard they just built a tunnel from England to France. The French
drive on the right hand side, the English on the left. Can they save
money by building only one lane?gjackson@athena.mit.edu (Gregory A. Jackson) (02/07/91)
Not strictly a virus, but as to software damaging hardware it was true under Windows 2.1 and WordPerfect 5.0 that running grab.com to capture an Paint image from the screen caused VGA monitors to snap, arc, oscillate, and (if you didn't shut it off immediately) burn out. - -- Greg Jackson 20B-140/MIT/Cambridge MA 02139 (617) 253-3712
71435.1777@CompuServe.COM (Bob Bosen) (03/01/91)
>Is it possible for a virus, etc to cripple physical hardware >components? Yes. I have first-hand experience with this, unfortunately. My experience goes back to about 1985, when I had the misfortune to buy one of the very first Compaq portables. These had an INEXCUSABLY weak power supply. (Every time I think back on the experience I start to get mad.) The power supply on even a bare-bones 128K Compaq was so marginal that it would blow a fuse if the video controller spent more than a few seconds issuing improper sync to the CRT. This happenned to me more than once as errant programs (mine and other programmers) diddled with the registers on the CRT controller card. I got to the point where I could recognize the pattern. First, the CRT would go nuts, kind of like your home TV when the "horizontal sync" knob is out of whack. My sensitive ears would pick up a high-pitched whine that other workers in my office couldn't hear. if I was REALLY REALLY fast I could switch off the power fast enough to save my power supply. But if I took more than about 3 seconds, WHAMMO! Instant tombstone. After 3 separate trips to Compaq-authorized service facilities, at about $300.00 a pop, (of course, this never happenned during the warrantee period, only immediately thereafter) I wised up and spied on the service technicians. They were just replacing a fuse that was SOLDERED onto the PC board. It was a big pain to disassemble that beast and find the fuse, but I never paid $300.00 again. After that I changed the fuse myself. About a year later, Compaq came out with a more reasonably designed power supply and I never suffered with this again (another $300.00 down the drain, though.) I conclude from this sorry chain of events that it definitely IS possible for malicious software to exploit weaknesses and quirks of hardware to cause damage, but I am also convinced that hardware that is properly designed should not suffer from these attacks. I believe there are probably a lot of computers out there with poorly designed hardware or with designs that take advantage of the public's desire to buy the cheapest stuff they can get. Lots of these systems could probably be damaged by malicious software, but I doubt if there is any single trick a bad guy can do in software that can be COUNTED on to damage the general population of PCs. I know of no flaw in the hardware that is widespread enough to be exploited in a general way. But a specific kind of PC or board or peripheral could be "targeted"..... - -Bob Bosen- Enigma Logic Inc. 2151 Salvio Street #301 Concord, CA 94520 USA Tel: (415) 827-5707 FAX: (415) 827-2593 Internet: 71435.1777@COMPUSERVE.COM