Security Basics mailing list archives

Re: Possible Bot?


From: Orlin Gueorguiev <orlin () baturov com>
Date: Tue, 13 May 2008 12:57:12 +0200

Hi,
From the second post I see that the targeted system is ns2.majordomo.ru. It 
seems that this is a Russian nameserver. It appears that the server is ok.
Still you might want to check the computer  and see which program is trying to 
ping that server.

Greetings,
Orlin

Tony Raboza wrote:
Hi,

I saw on our MRTG graph and monitoring tool that a PC on our LAN is
sending out large ICMP traffic to a public IP address.  Upon checking
on our Internet gateway, I saw this (output of tcpdump - I purposedly
changed the IP addresses):

18:00:02.788023 IP 1.2.3.4 (LANIP) > 4.5.6.7 (PUBLIC IP): ICMP echo
request, id 4, seq 59931, length 1480
18:00:02.788030 IP 1.2.3.4 (LANIP) > 4.5.6.7 (PUBLIC IP): icmp
18:00:02.798828 IP 1.2.3.4 (LANIP) > 4.5.6.7 (PUBLIC IP): ICMP echo
request, id 4, seq 60187, length 1480
18:00:02.798841 IP 1.2.3.4 (LANIP) > 4.5.6.7 (PUBLIC IP): icmp
18:00:02.809534 IP 1.2.3.4 (LANIP) > 4.5.6.7 (PUBLIC IP): ICMP echo
request, id 4, seq 60443, length 1480
18:00:02.809546 IP 1.2.3.4 (LANIP) > 4.5.6.7 (PUBLIC IP): icmp
18:00:02.820274 IP 1.2.3.4 (LANIP) > 4.5.6.7 (PUBLIC IP): ICMP echo
request, id 4, seq 60699, length 1480
18:00:02.820286 IP 1.2.3.4 (LANIP) > 4.5.6.7 (PUBLIC IP): icmp
18:00:02.831246 IP 1.2.3.4 (LANIP) > 4.5.6.7 (PUBLIC IP): ICMP echo
request, id 4, seq 60955, length 1480


Actually, this happened with this PC before - I had our helpdesk check
(its on a remote site) it for virus/worms but according to them
nothing turned up.

I'm thinking this might be a sign that this PC is part of a botnet?
How can I be certain?  And what kind of botnet/worm exhibit the
behavior as above?

Thank you very much.



Sincerely,
Tony


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