RE: SNMP attempts every 10 minutes

["Nhon Yeung" <Nhon.Yeung () cranegroup com au>]

Have you tried to use TCPview
<http://technet.microsoft.com/en-us/sysinternals/0e18b180-9b7a-4c49-8120
-c47c5a693683.aspx> on the workstation to work out what is sending the
snmp requests?

-----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com]
On Behalf Of k7 fantr
Sent: Tuesday, 15 January 2008 11:08 AM
To: Ivan .
Cc: security-basics () securityfocus com
Subject: Re: SNMP attempts every 10 minutes

- The switch logs indicate that IP x is failing to authenticate to it
(the switch).
- The IP x is a Windows 2000 workstation
- I do not know what is causing the attempt (trap or get) and I am not
sure how I could tell the difference via the logs:
"%SNMP-3-AUTHFAIL: Authentication failure for SNMP req from host
x.x.x.x (x.y.com)"
- I can not find any logs indicating anything regarding snmp on the
workstation
- I can re-create the same error message if I do a snmp-walk from my
workstation

Ultimately I am wondering if I am out of my mind to demand that due to
the suspicious behavior, and the inability to determine what it IS,
this workstation should be removed from the network and investigated
rather than left on the network until proved that it is something to
worry about.

and also if any knows of malicious code that behaves in this specific
manner?

I hope this adds a little clarity.. thanks for the follow ups



On Jan 14, 2008 5:43 PM, Ivan . <ivanhec () gmail com> wrote:
> Is it a SNMP-trap or SNMP-get request? There is a difference and your
> email isn't clear.
>
> SNMP-trap is sent by a device to a SNMP server
>
> SNMP-get is a read request from a SNMP poller to a device
>
> http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/snmp.htm
>
> I assume you mean a device is polling (SNMP-get) your core switch, and
> it does not have the correct auth string. You should be able to
> isolate the IP of the poller and they track down the box. It could be
> a linux box running some "snmp-walk" requests.
>
> cheers
> Ivan
>
>
> On 11 Jan 2008 20:33:27 -0000, <k7.fantr () gmail com> wrote:
> > There is a machine on our network that is trying and failing to
authenticate with the snmp trap on our core switch every 10 minutes. I
can not seem to isolate what is making the requests. Based on scans that
I have run, there is no know malware (nothing detected anyway). No
services running appear to stop the requests after being turned turned
off, and after installing a host based firewall and reviewing the logs,
as well as running wireshark and reviewing a 2 hour capture, I can not
seem to pin point anything making requests to that switch at all. It is
the only machine on the network of about 900 that is doing this.
> > I want the machine removed so that I can investigate further, but I
am getting resistance from the IT Manager and support (no time.. not
necessary..). Has anybody seen this before? Am I wrong to want this
removed?
> > Thanks in advance.


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