Security Incidents mailing list archives

Re: Strange SNMP probes suddenly appearing


From: <jcanaves () ucsd edu>
Date: 10 Dec 2003 23:31:30 -0000

In-Reply-To: <3FCD4909.5060605 () utc edu>

Originally, (I) Jeff Kell wrote:
Starting yesterday afternoon, I had a local student lab machine that was 
attempting to SNMP query our core router (it's default gateway), and due 
to a misconfiguration on the access-layer switch, I couldn't shut the 
port down, so I simply ACL'ed the address to Null.  It was sending 
queries every 10-15 seconds (somewhat irregularly).  It was a Windows 
machine (answered nbtscan) and nmap only revealed a NetBIOS port open, 
nothing else.  Suspecting a proxy, I scanned the PIX logs for the last 
24 hours and there was absolutely no traffic registered to/from the 
internet, and no active NAT xlate slot either.

After finally getting an ethereal trace of traffic from the faulty 
address (a machine using an Apple Airport) I found the following:

The first packet is an SNMP query directed to the router, community name 
'public', and attempts to read 3 MIBs:
  SNMPv2-MIB::sysName.0
  SNMPv2-MIB::sysLocation.0
  SNMPv2-MIB::sysDescr.0

I'm glad to hear that somebody experienced something similar to my three week nightmare. During the past 3 weeks my 
Cox@home service was disconnected due to several SNMP attacks against one of their Cox Business router originating from 
my IP address. After stopping SNMP in all my machines, scanning them for viruses and trojans, and increasing the 
security level of my firewall to the max, the problem still persisted. It did not ceased until I disconnected the 
Airport, but I am still in their blacklist and under 3 strike policy any other infraction could trigger the final 
cancellation of my high speed internet connection. Certainly, having that kid of BS going on is not a trivial issue.

Jeff, in case you figure out what is exactly going on with the Airports, may you contact me at jcanaves () ucsd edu

Thanks!

Jaume

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