[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <EA7C77F97CC73F4AAC856A4595DF34E205C472E1@swilnts801.wil.fusa.com>
From: Glenn_Everhart at bankone.com (Glenn_Everhart@...kone.com)
Subject: System monitor scheme - anyone know anything like this?
All -
In working up a scheme to authenticate one program to another, it occurred to me that it might
be useful to be able to be assured a piece of code has not been altered during its running, on
the basis of occasional probes. If something bashed a program in memory only (as with a buffer
overflow) this might stand a chance of noticing that this had been done.
To do such a check, one would have to have some piece of code that lives in a system and
is able to peek at the memory used as code storage by some process, checking that this
memory has not been altered since program load (which can't in general be done till load
occurs since addressing fixups at least are likely to have taken place). I suppose that instead
some code that checked the program counter of a target program and made sure that if it
were not in a shareable library or the kernel, that it was executing out of the range of addresses
that had been set up as in bounds for code segments of the program, could provide a similar
service.
It would be most convenient if it were not necessary to have the link maps and thus not necessary
to feed address bounds in by hand, by figuring out where the code ought to be loaded based on
the executable. Clearly it makes no sense to try to checksum (by whatever decent algorithm) data
areas. If however I had a daemon that could checksum code areas when it noticed a new program
was running (running some file I was interested in) and that checksummed the code areas now and
then later, it might notice memory attacks of some types. If it checked the PC also, it could notice
that execution might be going on off the stack, heap, etc. This probably will not cover all possible
bases of attack, but could cover enough to be worth using.
Has anyone seen such programs in their travels, or is this another build-it-myself project?
Thanks in advance for any who have suggestions.
Glenn C. Everhart
(everhart@....com home)
**********************************************************************
This transmission may contain information that is privileged, confidential and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. Thank you
**********************************************************************
Powered by blists - more mailing lists