Re: [Asrg] Countering Botnets to Reduce Spam
Rich Kulawiec <rsk@gsp.org> Fri, 14 December 2012 13:39 UTC
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Date: Fri, 14 Dec 2012 08:39:37 -0500
From: Rich Kulawiec <rsk@gsp.org>
To: Anti-Spam Research Group - IRTF <asrg@irtf.org>
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Subject: Re: [Asrg] Countering Botnets to Reduce Spam
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In addition to Chris's excellent comments: - Connecting a [Linux or other] server to a P2P network may not be possible or desirable in many/most instances. - Use of a technique like this might leak information on which software is installed, which versions, etc. - It will trigger false positives whenever software is upgraded/patched. (I say "will" because very long experience with tripwire and similar taught me this a long time ago.) - If the server has been subverted, then this mechanism can also be subverted. - Linux systems are not a significant component of botnets. I've been doing passive OS fingerprinting for most of a decade, and they're in the noise floor. It's still true now, as it was years ago, that bot-originated spam comes from Windows systems to about six 9's. - Better techniques already exist, such a firewalling outbound port 25 by default and only punching holes for systems that actually need to send mail. Another example: monitoring the TCP connection rate to port 25 on remote systems -- spam-senders are likely to push it much higher than "normal". ---rsk
- [Asrg] An Anti-Spam Heuristic Adam Sobieski
- Re: [Asrg] An Anti-Spam Heuristic Steve Atkins
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic John Levine
- Re: [Asrg] An Anti-Spam Heuristic Adam Sobieski
- Re: [Asrg] An Anti-Spam Heuristic John Levine
- [Asrg] The Real Problem (was: An Anti-Spam Heuris… Andrew Sullivan
- Re: [Asrg] An Anti-Spam Heuristic Rich Kulawiec
- Re: [Asrg] An Anti-Spam Heuristic Bill Cole
- Re: [Asrg] An Anti-Spam Heuristic Bart Schaefer
- Re: [Asrg] The Real Problem Chris Lewis
- Re: [Asrg] The Real Problem Alessandro Vesely
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Michael Thomas
- Re: [Asrg] The Real Problem (was: An Anti-Spam He… Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic John Leslie
- Re: [Asrg] An Anti-Spam Heuristic Seth
- Re: [Asrg] An Anti-Spam Heuristic Steve Atkins
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Steve Atkins
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Chris Lewis
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Michael Thomas
- Re: [Asrg] An Anti-Spam Heuristic Chris Lewis
- Re: [Asrg] An Anti-Spam Heuristic Chris Lewis
- [Asrg] Countering Botnets to Reduce Spam Adam Sobieski
- Re: [Asrg] Countering Botnets to Reduce Spam Chris Lewis
- Re: [Asrg] An Anti-Spam Heuristic Martijn Grooten
- Re: [Asrg] An Anti-Spam Heuristic Adam Sobieski
- Re: [Asrg] Countering Botnets to Reduce Spam Rich Kulawiec
- Re: [Asrg] Countering Botnets to Reduce Spam Adam Sobieski
- Re: [Asrg] Countering Botnets to Reduce Spam Chris Lewis
- Re: [Asrg] Countering Botnets to Reduce Spam Rich Kulawiec
- Re: [Asrg] An Anti-Spam Heuristic John Levine
- Re: [Asrg] An Anti-Spam Heuristic John Levine
- Re: [Asrg] Countering Botnets to Reduce Spam John Levine
- Re: [Asrg] An Anti-Spam Heuristic Chris Lewis
- Re: [Asrg] Countering Botnets to Reduce Spam Chris Lewis
- Re: [Asrg] Countering Botnets to Reduce Spam Chris Lewis
- Re: [Asrg] Countering Botnets to Reduce Spam Barry Shein
- Re: [Asrg] Countering Botnets to Reduce Spam Chris Lewis
- Re: [Asrg] An Anti-Spam Heuristic Alessandro Vesely
- Re: [Asrg] An Anti-Spam Heuristic Chris Lewis