Re: Anonymous LogOff and UDP Out Connections

From: GSimmonds (gsimmonds_at_primus.ca)
Date: 09/10/03

  • Next message: Sebastian Schneider: "Re: Cisco vs. Snort"
    To: "Security-Basics@Securityfocus. Com" <security-basics@securityfocus.com>
    Date: Tue, 9 Sep 2003 20:12:55 -0400
    
    

    ----- Original Message -----
    From: "Mark Sargent" <powderkeg@snow.email.ne.jp>
    To: "Security-Basics@Securityfocus. Com" <security-basics@securityfocus.com>
    Sent: Tuesday, September 09, 2003 1:14 AM
    Subject: Anonymous LogOff and UDP Out Connections

    > Hi All,
    >
    > When activating the LAN, I notice numerous UDP packet attempts to a number
    > of different IPs,
    > on the Host machine. All attempts are from the localhost on port 137 to
    > owner;stystem on 137. What are thse attempts.

    It looks like NetBIOS name resolution. From your previous post, I'm assuming
    that your Host is multihomed. There's an article you may be interested in
    about unbinding NetBIOS from your external NIC.
    http://www.practicallynetworked.com/sharing/securnet.htm

    >Also, I'm seeing numerous
    > LogOff alerts in Security Event Viewer.

    I have no experience in this matter but these might help...
    www.eventid.net
    http://www.eventlogscan.com/

    > I'm also getting a lot of attempts from the Client, 192.168.0.2 to connect
    > to port localhost on port 53, UDP(there is no owner). What is all of
    this..?
    > I'm stealthed according to the security checks here on this site and
    > grc.com. Any help appreciated. Cheers.
    >
    > OS = Win2kPro(both Host(192.168.0.1) and Client(192.168.0.2))
    > Firewall = Kerio
    > Connection = ISDN

    Were you able to sort out your Client accessing web sites? It looks like
    your Client is attempting DNS lookups. You might also see Dest.
    Unreachables since it isn't getting a response.

    Now my experience with ICS is theoretical, but I plan on setting one up soon
    and I use Kerio. A few things you could check...
    Have you configured the MS Networking tab in Administration?
    Does IE on the client know where the gateway is?
    Have you written a rule to allow TCP and UDP traffic to and from your
    client?
    Let me know how it goes.

    Regards
    Gary

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  • Next message: Sebastian Schneider: "Re: Cisco vs. Snort"

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