Re: Proxy attackers/hijackers

From: Joe Stewart (jstewart_at_lurhq.com)
Date: 10/17/03

  • Next message: Alvin Wong: "Re: New Rootkit?"
    To: General DShield Discussion List <list@dshield.org>
    Date: Fri, 17 Oct 2003 10:15:37 -0400
    
    

    On Thursday 16 October 2003 11:31 pm, Jeff Kell wrote:
    > We had an attempted proxy rape today on a trojanned dorm machine. No
    > mail escaped thanks to firewalling but I did track down the culprits
    > and the compromised ports (which appear random, they changed when the
    > machine was rebooted). Do not have the machine (yet) for forensics
    > to see what infected it, but it was providing two proxy ports on
    > random ports that change when the machine is rebooted (apparently,
    > given the time difference between the pairs of proxy ports below).

    If the two proxy ports start at a random port but themselves are
    sequential, it could be the Autoproxy trojan. A rash of these was
    installed yesterday by a second mass-hack of a large webhosting
    provider. Autoproxy can be detected when it attempts to make outbound
    HTTP control connections (one is to a CGI script where it reports its
    port numbers and stats, the other is to an uninvolved third-party
    website for connectivity checking). In these connections it sets its
    User-Agent header to "Autoproxy/0.2". The snort signature below will
    catch these connections leaving your network and let you know if you
    have any infected hosts.

    alert tcp $HOME_NET any -> $EXTERNAL_NET 80 (msg:"Autoproxy Trojan
    control connection"; flags:A+; content: "|0d 0a 55 73 65 72 2d 41 67 65
    6e 74 3a 20 41 75 74 6f 70 72 6f 78 79 2f|";
    reference:url,www.lurhq.com/autoproxy.html; classtype:trojan-activity;
    sid:1000028; rev:1;)

    -Joe

    -- 
    Joe Stewart, GCIH 
    Senior Security Researcher
    LURHQ http://www.lurhq.com/
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  • Next message: Alvin Wong: "Re: New Rootkit?"

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