Security Incidents mailing list archives

Re: Tracking down the still infected hosts

From: "Mike Lewinski" <mike () rockynet com>
Date: Mon, 24 Sep 2001 10:29:12 -0600

Anyone else doing anything to help this?


I don't think that this has been posted here yet.... The following appears
to cripple infected hosts and limits the damage they can cause. Others who
have used this report that persistent infected hosts disappear from their
logs shortly after applying this configuration change to their own servers,
and that browsing an infected server after applying this results in "HTTP
403.9 - Access Forbidden: Too many users are connected"

For Apache:
RedirectMatch (.*)\cmd.exe$ http://127.0.0.1


For IIS:

----- Original Message -----
From: "Ron Hornbaker" <ron () hksi net>
To: <imail () hksi net>
Sent: Friday, September 21, 2001 1:11 PM
Subject: RE: [imail] IIS Judo against Nimda's DoS attacks (was Fwd:
[isp-linux] Buaaa Haaa Ha Haaaaaaaaa...)

Great tip, Len. Here's the IIS version... just create a file in your web
root called something like "Custom404.asp", with this content (customize
the friendly part as much as you wish):


<%
'Custom404.asp page to thwart Nimda DoS attacks on IIS
'by Humankind Systems, Inc. http://hksi.net/
'No support or guarantees of any kind are granted with this
'code. Use at your own risk. Distribute freely.

'Get the entire URL requested
myRequest=Request.ServerVariables("QUERY_STRING")

'A list of filenames Nimda looks for
myBadList="cmd.exe,root.exe,admin.dll,default.ida"

'Detect a GET request from the Nimda virus and take appropriate action
arrBadString=Split(myBadList,",")
for i=0 to UBound(arrBadString)
if inStr(myRequest,arrBadString(i))>0 then
'turn offending server back on itself
Response.redirect "http://127.0.0.1";
end if
next
%>
<html>
<head>
<title>Page Not Found</title>
</head>
<body>
Sorry, but that page was not found on our server.
<p>
Here is a link back to our <a href="/">Home Page</a>.
</body>
</html>




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Current thread:

Tracking down the still infected hosts Darren Windham (Sep 24)
- Re: Tracking down the still infected hosts Mike Lewinski (Sep 24)
- <Possible follow-ups>
- RE: Tracking down the still infected hosts Martinez, Simon (Sep 24)
- RE: Tracking down the still infected hosts Fulton L. Preston Jr. (Sep 24)
  - RE: Tracking down the still infected hosts Ryan McDonnell (Sep 25)
  - Re: Tracking down the still infected hosts Kyle R. Hofmann (Sep 25)
    - Re: Tracking down the still infected hosts Tina Bird (Sep 25)
    - Re: Tracking down the still infected hosts Skip Carter (Sep 25)
    - Re: Tracking down the still infected hosts Kyle R. Hofmann (Sep 25)
    - Re: Tracking down the still infected hosts Dale Lancaster (Sep 25)
    - Re: Tracking down the still infected hosts Duncan Hill (Sep 25)
    - Re: Tracking down the still infected hosts Josh Burroughs (Sep 25)

(Thread continues...)