[net.micro] MS-DOS tool to help detect Trojan Horse programs

nather@ut-sally.UUCP (Ed Nather) (04/10/86)

I have posted a program to net.sources which searches MS-DOS executable
files for ASCII strings and sends them to stdout.  It is modeled after the
Unix utility "strings" to operate in the more chaotic MS-DOS environment.
While it is not a general "Trojan Horse" detector it can find typical kinds
of "gloats" left by the terrorist.  It readily found the infamous Microsoft
"...bitter fruit -- Trashing Disk" message in MS Word, for example.

If the terrorist does not include a gloating message, of course, this program
won't help -- but what good is wanton destruction if you can't gloat about it?

-- 
Ed Nather
Astronomy Dept, U of Texas @ Austin
{allegra,ihnp4}!{noao,ut-sally}!utastro!nather
nather@astro.AS.UTEXAS.EDU

peter@gumby.UUCP (Peter Wu) (04/11/86)

It won't be long before people start to write trojan horse
programs with encrypted ascii strings so looking for ascii
strings in .exe files won't do any good.

peter

woolsey@umn-cs.UUCP (Jeff Woolsey) (04/17/86)

Trojan horse programs with (nominally-)encrypted strings are not new.  Our
site got bit by one last April.  Someone had stuck code in /etc/update
to write HAPPY APRIL FOOL'S DAY in /etc/motd every 10 minutes.  We couldn't
find that string in any of the running processes.  If the message did not
also include a line of asterisks I never would have found it.  There was
a line of some other character of the same length in /etc/update.
-- 
-- 
"Clorox bottles!  Millions of MY Clorox bottles!  This is where they hid 'em--
 Zeigler and Kissinger.  I'll get 'em on the way back!"

				Jeff Woolsey
				...ihnp4{!stolaf}!umn-cs!woolsey
				woolsey@umn-cs.csnet