Re: Help - a possible bot

["Moshe Aelion" <ma0934 () hotmail com>]

HC

Referring to parts of your message:

> "However, the fact that your system is responding would be indicative of
something else, possibly w/ your ZA installation".
What do you mean by that, and how can I confirm/disprove it?

> Also, since your logs don't show an ICMP port unreachable response (your
system sent out a UDP datagram), that would indicate that, in fact, >the
source IPs are NOT spoofed.
The source addresses are completely random, and they turn up absolutely
nothing in a  reverse resolution and WHOIS queries. In fact, this is
happening only with the source IP addresses of the probes to which the PC is
trying to respond; the other probes, ignored by the PC, have a resolved host
name (you can see it in the ZA log attached). I think this is very
suspicious - in fact, it's a pretty unique and discernible behavior - is
anyone familiar with a bot/Trojan behaving this way?

> Is there anything besides the traffic you posted that would lead you to
believe that you had something installed on your system?
Like I mentioned above: 1. The immediate response attempt to the probe; and
2. The fact that when the Internet is on-line, the explorer and svchost
processes are constantly active, with I/O of 25-30 kbps. This ceases when I
go off-line.

Is this behavior similar to any known bot infection?

Thanks in advance

Moshe


---------------------------------- Original
Message ----- ----------------------------------------
From: H C
To: incidents () securityfocus com
Sent: Saturday, November 16, 2002 3:10 PM
Subject: re: Help - a possible bot


> The problem is, I am detecting a suspicious
hit/respond
> activity, which, in my opinion, points to an active
> bot.

No offense, dude, but you're freaking out over
nothing.  Based on the information you provided, there
IS no bot (remember "The Matrix"?  "There is no
spoon").

> Here's the evidence: when inspecting ZA logs, you
can
> see a blocked scan (coming every couple of minutes,
> from arbitrary addresses

The "scans" you're referring to look like NetBIOS name
scans...queries to UDP port 137.  On normal MS
networks, these "scans" would originate from UDP port
137, as well.  So...they MAY be scans of some kind.
However, the fact that your system is responding would
be indicative of something else, possibly w/ your ZA
installation.

> - I bet they're spoofed

Well, that's not "evidence", now, is it?  Also, since
your logs don't show an ICMP port unreachable response
(your system sent out a UDP datagram), that would
indicate that, in fact, the source IPs are NOT
spoofed.

Also, there's nothing in the netstat and fport outputs
that you sent that seem to indicate that you have any
sort of bot or trojan at all.  Is there anything
besides the traffic you posted that would lead you to
believe that you had something installed on your
system?

HTH






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