how to check for a compromised system

Bill Moran wmoran at
Wed Jun 28 12:57:58 UTC 2006

In response to "Brent" <mrb at>:

> Hello,
> Im running several servers all ranging from FBSD 4.11 through the 5.4 release
> , patched of course. MY question is how do i check a system to see if has been
> compromised ? I have already run a current version "chkrootkit" & found nothing.

You need to plan ahead and install Samhain (or equiv) on the machines _before_
they're deployed so you can detect unauthorized changes.

> The symptom im seeing is yesterday all of a sudden the root user was removed
> from the /etc/passwd file & Im not sure on how to track down what happened. I
> managed to recover from this. Are there any other tools that i can use to
> track down say who did what on the box? files that may have changed & time &
> dates...

Yeah, Samhain and its class of software.  Unfortunately, you have to have
it set up _before_ this happens in order for it to be useful.

Bill Moran
Collaborative Fusion Inc.

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