Re: fun with posiden rootkit

From: Dave Dittrich (dittrichat_private)
Date: Mon Mar 25 2002 - 23:36:33 PST

  • Next message: zeno: "Re: watching them -after the fact"

    On Mon, 25 Mar 2002, Skip Carter wrote:
    
    > > - sometimes checking failed script-kiddies can be entertaining if time
    > >   permits to look around for any funny stuff
    >
    >   I had one incident that I investigated for a client recently.
    >
    >   It was the usual: gain entry, install rootkit, install password
    >   scanner, etc.  Except he did it in the wrong order, so that his
    >   password scanner caught his own connection back to his rootkit
    >   archive; so when I started my investigation I was able to log in
    >   to his archive and pick up his entire stash of tools.
    
    I can't tell you how many times I've seen that over the years,
    e.g.:
    
    	http://staff.washington.edu/dittrich/talks/security/case1/hacksniff.txt
    
    This kind of thing is, according to an Assistant US Attorney, "a slam
    dunk" violation of the Wiretap statute.  With a little correlation
    of events via timestamps on files and other logins in the sniffer
    file, you can show a direct link between an intruder, the sniffer,
    and the "fruits of crime" (the sniffed passwords).  If you can get
    the owner of the site to save a copy for law enforcement (rather than
    popping in yourself and copying files), there is corroborating
    evidence from an independant source.
    
    Then again, I've also seen the following:
    
    /*
     * dontsniff2.c by XXXXXXXX (today: 13 Nov 1998)
     * Regards to both XXXXXX and XXXXXXX ;)
     * Paper:
     *  T.Ptacek, T.Newsham "Insertion, Evasion, and Denial of Service: Eluding
     *  Network Intrusion Detection," Secure Networks, Inc. January, 1998
     * Greetings to XXX@!#$
     * Description:
     *  this daemon add little protection from some kind of sniffers and IDS
     * How it work (in default mode: -fffdFD):
     *  1. send fake data packets with random garbage on every ACK packet -
     *      - sniffer log fake data.
     *  2. send fake FIN packets on every SYN packet -
     *      - sniffer "think" connection closed and stop logging.
     * "fake" mean - it good packets for sniffer but really ignored by most
     *   of computer systems in internet cause they have invalid sequence number.
     */
    
    Moral of the story: don't expect to be lucky all the time, and trust
    packets found on the network, not files found on a compromised host.
    
    --
    Dave Dittrich                           Computing & Communications
    dittrichat_private             University Computing Services
    http://staff.washington.edu/dittrich    University of Washington
    
    PGP key      http://staff.washington.edu/dittrich/pgpkey.txt
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