>
>
>Date: Sat, 12 Jun 2004 13:15:33 +0200
>From: "Peter Rosa" <prosa@pro.sk>
>Subject: Hacked or not ?
>To: "FreeBSD Security" <freebsd-security@freebsd.org>
>Message-ID: <016301c4506e$947644e0$3501a8c0@pro.sk>
>
>Hi all,
>
>please advice me - I was on holidays for one week. After return I found in
>security mails from router (chkrootkit) following message:
>Checking `lkm'... You have 1 process hidden for readdir command
>You have 1 process hidden for ps command
>Warning: Possible LKM Trojan installed
>
>It apeared only onece. From previous and next days reports, the message is
>not present.
>
>How could I be sure, the machine is not hacked ?
>
>
[1] Make backups. tar(1), dump(8), doesn't matter.
[2] Reinstall identical operating system on new equipment.
[3] Restore backups into large partition sized for this operation
(call it '/backups').
[4] Compare the contents of each directory in /backups recursively
against a known
good copy, For example, to compare /usr against the backed-up
image, do this:
# diff -r /usr /backups/usr
[5] Review the list for files which differ or which do not exist on
the known good copy.
[6] Exclude files for which there are good reasons for difference (IE,
logs and state files).
[7] Analyze the resulting files; pay particular attention to
executables, but also libraries.
You may also find it useful to reload the old operating system onto a
box on an insulated network and monitor the operating system, its
processes and its network traffic, using known good tools.
Regards,
-- richard
--
Richard Childers / Senior Engineer
Daemonized Networking Services
945 Taraval Street, #105
San Francisco, CA 94116 USA
[011.]1.415.759.5571
http://www.daemonized.com
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