Re: Tracking down the still infected hosts

From: Dale Lancaster (daleat_private)
Date: Tue Sep 25 2001 - 13:34:37 PDT

  • Next message: Ryan Russell: "Re: Tracking down the still infected hosts"

    A Redirect permanent directive seems to have done it for our site.  Nimda
    traffic has gone way down. A standard "redirect", considered temporary,
    would probably not do it.
    
    However I am seeing new log entries that I haven't seen before:
    
    [Tue Sep 25 16:33:41 2001] [error] [client 199.26.11.171] File does not
    exist: /some/where/html/_vti_bin/shtml.exe/_vti_rpc
    
    It may just be some misconfiguration in our site, but the shtml.exe seems to
    point to something else since we don't use .exe stuff on our site.  These
    are flooding my site, but we get lots of them over a day.
    
    dml
    ----- Original Message -----
    From: "Kyle R. Hofmann" <krhat_private>
    To: <incidentsat_private>
    Sent: Tuesday, September 25, 2001 3:28 PM
    Subject: Re: Tracking down the still infected hosts
    
    
    > On Tue, 25 Sep 2001 11:24:49 -0500, Tina Bird wrote:
    > > According to Ryan Russell (who's been analyzing the
    > > worm code), Nimda doesn't honor redirects - it just
    > > checks the response it gets from a Web server to
    > > determine whether or not the server is vulnerable.
    > > It doesn't follow redirects.  So what does this
    > > actually accomplish?
    >
    > Actually, I'm not sure it accomplishes anything.  I read the post saying
    that
    > redirecting Nimda to 127.0.0.1 killed it or slowed it down, and I wrote
    and
    > posted my redirection tool before I spent a lot of time watching Nimda's
    > reaction to it.  Now that I've let it run overnight, I'm convinced that it
    > doesn't do any good.  Nimda traffic on my machine has actually gone up,
    > because now it doesn't stop--it just keeps pounding on me, gleefully
    ignorning
    > the redirects.  I've gotten about 1.44 HTTP connections per minute in the
    > past six hours, primarily from two persistent machines, whereas yesterday,
    > before I had written my tool, I got about 0.391 connections per minute
    spread
    > out among a half-dozen or so machines.  Since none of this is legitimate
    > traffic (my machine hasn't run a web server in half a year), for machines
    > that don't run web servers it's clearly less effective to send redirects
    than
    > to simply refuse connections.  I suspect that the same is true for web
    > servers, as well.
    >
    > --
    > Kyle R. Hofmann <krhat_private>
    >
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