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