How to Detect the ::$DATA Attack in IIS Log Files

ID: Q197464

The information in this article applies to:

Microsoft Internet Information Server versions 1.0, 2.0, 3.0, 4.0

SUMMARY

As a result of the problem with Internet Information Server (IIS) and NTFS Alternate Data Streams that is referenced at http://www.microsoft.com/security/bulletins/ms98-003.htm, administrators may wish to determine if their server was "attacked" by Internet users attempting to gain access to source text.

MORE INFORMATION

IIS is configured by default to log access to the server. When logging is enabled and a request is made from a browser to IIS using Alternate Data Streams (for example http://myserver/file.asp::$DATA), IIS writes this information to the log file. By analyzing the log files kept by the server, any attempted access to source code can be determined.

The following examples show what a request to the "/default.asp" page of a server would look like if an attempt was made to view the file's source code:

   W3C Extended Log File Format:

      11:25:12 10.0.0.5 GET /default.asp::$DATA 200
      11:26:07 10.0.0.5 GET /default.asp::$DATA 304
      11:54:04 10.0.0.5 GET /default.asp::$DATA 200

   NCSA Common Log File Format:

      10.0.0.5 - - [02/Jul/1998:11:25:12 -0600] "GET /default.asp::$DATA
      HTTP/1.1" 200 13388
      10.0.0.5 - - [02/Jul/1998:11:26:07 -0600] "GET /default.asp::$DATA
      HTTP/1.1" 304 123
      10.0.0.5 - - [02/Jul/1998:11:54:04 -0600] "GET /default.asp::$DATA
      HTTP/1.1" 200 12219

   Microsoft IIS Log File Format:

      10.0.0.5,-
      ,02/Jul/1998,11:25:12,W3SVC,SERVER1,10.0.0.2,163,13388,200,0,GET,/de
      fault.asp::$DATA
      10.0.0.5,-
      ,02/Jul/1998,11:26:07,W3SVC,SERVER1,10.0.0.2,163,123,304,0,GET,/defa
      ult.asp::$DATA
      10.0.0.5,-
      ,02/Jul/1998,11:54:04,W3SVC,SERVER1,10.0.0.2,163,12219,200,0,GET,/de
      fault.asp::$DATA

For more information on Alternate Data Streams, see the following articles in the Microsoft Knowledge Base:

   ARTICLE-ID: Q188806
   TITLE     : NTFS Alternate Data Stream Name of a File May Return Source

   ARTICLE-ID: Q105763
   TITLE     : HOWTO: Use NTFS Alternate Data Streams

Keywords          :  
Version           : WINNT:1.0,2.0,3.0,4.0
Platform          : winnt
Issue type        : kbhowto