act@softserver.canberra.edu.au (Andrew Turner) (04/18/91)
We have serious virus problems on our campus PC's. I need to be able to prevent users breaking out of AUTOEXEC.BAT by using CTRL-C/CTRL-BRK and also to prevent CTR-ALT-DEL use so that our anti-viral software has a chance to do its stuff. Both technical advice and advice as to the availability of PD/Shareware is sought. I am able to write a CTRL-C handler however I would welcome any input. We run 286's and 386sx's all with hard disks. Are there any device drivers that can help solve this problem by getting control before AUTOEXEC.BAT is run. I seem to remember seeing stuff about this recently and did not heed the it then. Many Thanks in advance -- Andrew Turner :-) | E-mail : act@csc.canberra.edu.au Comp. Services Centre | +61 6 2522414 / +61 6 2522401 University of Canberra |________________ fax +61 6 2522400 P.O. Box 1 BELCONNEN ACT 2616 AUSTRALIA |
timmons@atccad.enet.dec.com (04/19/91)
Try this - Load MSDOS.SYS into debug and
search for CD 23. It may be in more than one place. The right
place should look like this F8 CD 23 FA (CLC, INT 23, CLI). Just
change the correct CD 23 to 90 90 (NOP, NOP) and write it back out.
Use that MSDOS.SYS on your disk. Uh, one minor problem, I don't
think Microsoft approves of people distributing hacked versions
of their operating system. So consult your lawyer before doing this.
Also, you might need to re-enable Ctrl-C. You could write a little
program called from your batch file (the last line) that pops CD 23
back into memory where it should be.
Hmm... all this sounds as bad as a virus!
Ray T.