Quoting Ryan O'Rourke <tclug at ryanorourke.org>: > I don't understand what good that does if your system has been rooted > though. Why can't an attacker just change those saved binaries as well? > > Well, after booting from a Knoppix cd, mounting my drives, and running > chkrootkit on them I get "Checking 'su' ... INFECTED". Not a good sign. > > Now the question is - how do I go about figuring out how it was done? > What kind of forensics can I do to turn this into a learning > experience before I reformat and reinstall? First, I'm glad you realize the need to reload this machine. A lot of people want to save a compromised machine, not recommended. As far as learning, check to see if you have any unpatched services or an unpatched kernel. Also, chkrootkit should give you an idea of what was used on your system. A lot of those tools will target a specific vulnerability. Try checking the history file for root. Check out the logs, you may see some sort of irregularity which can help you identify when things went down, possibly even something letting you know what happened. The amount of learning that you will be able to do will be dependant on how good the person who compromised your machine was. If they were clueful at all the history file will be removed after they logout, the logs will be cleansed and you will be lucky to figure out how they got in. In this case refer back to the vulnerable services and make a best guess. > I'm kind of suspecting that one of my Windows users may be at fault > here. Is it possible that one of them may have been compromised first > and then the attacker used a password or key found in WinSCP to > compromise my system? Or is it more likely the attack just came from > the Internet directly through my one open port, past my router, past > my firewall, and breached that way? All things are possible, but a direct compromise is probably more likely. If you are running anything with a vulnerabilty and a known remote exploit, look for a direct compromise. If not, look for anything with a privelege escalation vulnerability, including the kernel. Josh _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota Help beta test TCLUG's potential new home: http://plone.mn-linux.org Got pictures for TCLUG? Beta test http://plone.mn-linux.org/gallery tclug-list at mn-linux.org https://mailman.real-time.com/mailman/listinfo/tclug-list