Recommended Posts

I've recently been getting a perculiar kind of spam, I'm having a little trouble figuring out why it's avoiding the spam filter.

My email setup: I'm using google apps. I have records for SPF (the generic google one), DKIM (unique), and DMARC. My DMARC policy is using default values (but p=quarantine), which uses relaxed alignment mode for both SPF and DKIM as well as letting mail through if either passes (to avoid f/p of forwarding servers).

Basically, this new spam claims to come from my own domain, which it obviously isn't. Now usually this wouldn't be a problem since it should fail both SPF and DKIM. But it looks like this breed is passing (or at least not failing) SPF for some reason. I'm referring specifically to "Received-SPF" and "Authentication-Results", which makes it look like they're using a Gmail account to originate the spam, but the Gmail account itself obviously can't spoof email addresses on my domain. Later down it appears that they are, in fact, using a third party sender, but how does it pass SPF?

I'm quite confused about this header, could anyone with more experience in this area shed some light as to what's actually happening? Is there any change I can make to the DMARC policy to filter this out?

Thanks!


Delivered-To: [email protected]
Received: by 10.223.161.66 with SMTP id q2csp29576fax;
Sat, 16 Feb 2013 13:11:56 -0800 (PST)
X-Received: by 10.220.116.5 with SMTP id k5mr9087041vcq.55.1361049116195;
Sat, 16 Feb 2013 13:11:56 -0800 (PST)
Return-Path: <[email protected]>
Received: from 201-212-133-238.cab.prima.net.ar (201-212-133-238.cab.prima.net.ar. [201.212.133.238])
by mx.google.com with ESMTP id a1si13647855vdk.21.2013.02.16.13.11.54;
Sat, 16 Feb 2013 13:11:56 -0800 (PST)
Received-SPF: neutral (google.com: 201.212.133.238 is neither permitted nor denied by domain of [email protected]) client-ip=201.212.133.238;
Authentication-Results: mx.google.com;
spf=neutral (google.com: 201.212.133.238 is neither permitted nor denied by domain of [email protected]) [email protected]
Message-ID: <[email protected]>
Date: Sat, 16 Feb 2013 18:25:48 -0300
From: <[email protected]>,
<[email protected]>,
<[email protected]>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en; rv:1.9.2.12) Gecko/20101027 Thunderbird/3.1.6
MIME-Version: 1.0
To: <[email protected]>,
<[email protected]>,
<[email protected]>
Subject: Take a spare three-hour work week in our clinic and get 580 dollars.
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
[/CODE]

Link to comment
https://www.neowin.net/forum/topic/1136888-help-analyzing-email-header/
Share on other sites

It might be this address:


[email protected] and/or
[email protected]
[/CODE]

Which you got this today or yesterday... then next email you will get same address with random numbers such as 145, 160, 134... which is why you still get spam in your inbox. If you want to block them... block them with any words you might find in the body or subject line... such as viagra, so you can add them to your blacklist.

gmail spf is not very locked down, if you check that IP against it - if you check any IP against it comes up as neutral

201.212.133.238 may send in the name of the domain.

  • SPF check start.
    • Domain: gmail.com

    [*]Getting SPF (TXT) record.

    [*]Found SPF record.

    [*]SPF policy record data:

    • v=spf1 redirect=_spf.google.com

    [*]Evaluating SPF policy:

    • v=spf1 redirect=_spf.google.com

    [*]Policy parsed OK, no warnings.

    [*]Evaluating SPF policy string.

    • Following the "redirect" modifier.
      • Argument domain-spec: _spf.google.com

      • Domain argument after macro expansion:
        • _spf.google.com

      • SPF check start.
        • Domain: _spf.google.com

      • Getting SPF (TXT) record.

      • Found SPF record.

      • SPF policy record data:
        • v=spf1 include:_netblocks.google.com include:_netblocks2.google.com include:_netblocks3.google.com ?all

      • Evaluating SPF policy:
        • v=spf1 include:_netblocks.google.com include:_netblocks2.google.com include:_netblocks3.google.com ?all

      • Policy parsed OK, no warnings.

      • Evaluating SPF policy string.
        • Evaluating SPF mechanism "include".
          • Prefix: Pass.

          • Argument domain-spec: _netblocks.google.com

          • Domain argument after macro expansion:
            • _netblocks.google.com

          • SPF check start.
            • Domain: _netblocks.google.com

          • Getting SPF (TXT) record.

          • Found SPF record.

          • SPF policy record data:
            • v=spf1 ip4:216.239.32.0/19 ip4:64.233.160.0/19 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:209.85.128.0/17 ip4:66.102.0.0/20 ip4:74.125.0.0/16 ip4:64.18.0.0/20 ip4:207.126.144.0/20 ip4:173.194.0.0/16 ?all

          • Evaluating SPF policy:
            • v=spf1 ip4:216.239.32.0/19 ip4:64.233.160.0/19 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:209.85.128.0/17 ip4:66.102.0.0/20 ip4:74.125.0.0/16 ip4:64.18.0.0/20 ip4:207.126.144.0/20 ip4:173.194.0.0/16 ?all

          • Policy parsed OK, no warnings.

          • Evaluating SPF policy string.
            • Evaluating SPF mechanism "ip4".
              • Prefix: Pass.

              • Argument network-spec: 216.239.32.0

              • Argument ip4-cidr-length: 19

            • Evaluating SPF mechanism "ip4".
              • Prefix: Pass.

              • Argument network-spec: 64.233.160.0

              • Argument ip4-cidr-length: 19

            • Evaluating SPF mechanism "ip4".
              • Prefix: Pass.

              • Argument network-spec: 66.249.80.0

              • Argument ip4-cidr-length: 20

            • Evaluating SPF mechanism "ip4".
              • Prefix: Pass.

              • Argument network-spec: 72.14.192.0

              • Argument ip4-cidr-length: 18

            • Evaluating SPF mechanism "ip4".
              • Prefix: Pass.

              • Argument network-spec: 209.85.128.0

              • Argument ip4-cidr-length: 17

            • Evaluating SPF mechanism "ip4".
              • Prefix: Pass.

              • Argument network-spec: 66.102.0.0

              • Argument ip4-cidr-length: 20

            • Evaluating SPF mechanism "ip4".
              • Prefix: Pass.

              • Argument network-spec: 74.125.0.0

              • Argument ip4-cidr-length: 16

            • Evaluating SPF mechanism "ip4".
              • Prefix: Pass.

              • Argument network-spec: 64.18.0.0

              • Argument ip4-cidr-length: 20

            • Evaluating SPF mechanism "ip4".
              • Prefix: Pass.

              • Argument network-spec: 207.126.144.0

              • Argument ip4-cidr-length: 20

            • Evaluating SPF mechanism "ip4".
              • Prefix: Pass.

              • Argument network-spec: 173.194.0.0

              • Argument ip4-cidr-length: 16

            • Evaluating SPF mechanism "all".
              • Prefix: Neutral.

            • SPF mechanism "all" matched with prefix Neutral.

          • Finished evaluating SPF policy.

          • SPF policy evaluation finished with SPF Neutral.

        • Evaluating SPF mechanism "include".
          • Prefix: Pass.

          • Argument domain-spec: _netblocks2.google.com

          • Domain argument after macro expansion:
            • _netblocks2.google.com

          • SPF check start.
            • Domain: _netblocks2.google.com

          • Getting SPF (TXT) record.

          • Found SPF record.

          • SPF policy record data:
            • v=spf1 ip6:2001:4860:4000::/36 ip6:2404:6800:4000::/36 ip6:2607:f8b0:4000::/36 ip6:2800:3f0:4000::/36 ip6:2a00:1450:4000::/36 ip6:2c0f:fb50:4000::/36 ?all

          • Evaluating SPF policy:
            • v=spf1 ip6:2001:4860:4000::/36 ip6:2404:6800:4000::/36 ip6:2607:f8b0:4000::/36 ip6:2800:3f0:4000::/36 ip6:2a00:1450:4000::/36 ip6:2c0f:fb50:4000::/36 ?all

          • Policy parsed OK, no warnings.

          • Evaluating SPF policy string.
            • IP6 mechanism evaluation is not implemented.

            • IP6 mechanism evaluation is not implemented.

            • IP6 mechanism evaluation is not implemented.

            • IP6 mechanism evaluation is not implemented.

            • IP6 mechanism evaluation is not implemented.

            • IP6 mechanism evaluation is not implemented.

            • Evaluating SPF mechanism "all".
              • Prefix: Neutral.

            • SPF mechanism "all" matched with prefix Neutral.

          • Finished evaluating SPF policy.

          • SPF policy evaluation finished with SPF Neutral.

        • Evaluating SPF mechanism "include".
          • Prefix: Pass.

          • Argument domain-spec: _netblocks3.google.com

          • Domain argument after macro expansion:
            • _netblocks3.google.com

          • SPF check start.
            • Domain: _netblocks3.google.com

          • Getting SPF (TXT) record.

          • Found SPF record.

          • SPF policy record data:
            • v=spf1 ?all

          • Evaluating SPF policy:
            • v=spf1 ?all

          • Policy parsed OK, no warnings.

          • Evaluating SPF policy string.
            • Evaluating SPF mechanism "all".
              • Prefix: Neutral.

            • SPF mechanism "all" matched with prefix Neutral.

          • Finished evaluating SPF policy.

          • SPF policy evaluation finished with SPF Neutral.

        • Evaluating SPF mechanism "all".
          • Prefix: Neutral.

        • SPF mechanism "all" matched with prefix Neutral.

      • Finished evaluating SPF policy.

      • SPF policy evaluation finished with SPF Neutral.

    • Returned from redirection.

    [*]Finished evaluating SPF policy.

    [*]SPF policy evaluation finished with SPF Neutral.

So did a test with just random ****.. 1.2.3.4 may send in the name of the domain.

http://vamsoft.com/s...f-policy-tester

You can use this is well http://www.kitterman...f/validate.html, you can pretty much test anything with a gmail.com domain and you get neutral..

if you notice their record

v=spf1 include:_netblocks.google.com include:_netblocks2.google.com include:_netblocks3.google.com ?all

So since using ?, they never fail anything - so what is the point of the policy?? ;) They really should have a - for their policy.

Each mechanism can be combined with one of four qualifiers:

  • + for a PASS result. This can be omitted; e.g., +mx is the same as mx.
  • ? for a NEUTRAL result interpreted like NONE (no policy).
  • ~ (tilde) for SOFTFAIL, a debugging aid between NEUTRAL and FAIL. Typically, messages that return a SOFTFAIL are accepted but tagged.
  • - (minus) for FAIL, the mail should be rejected (see below).

your hopeless using spf to filter on - its going to be neutral.. But sure there is something else you could filter on.. is the spam all coming from that IP? Got to be some key words to block.. Can you just report as spam, normally gmail updates their filtering.

This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Posts

    • Just for anyone reading, AdGuard (the free, standalone MV3 extension) is quite good now, a direct competitor to uBlock Origin Lite and much more built-out than it.
    • Microsoft Edge 149.0.4022.62 by Razvan Serea Microsoft Edge is a super fast and secure web browser from Microsoft. It works on almost any device, including PCs, iPhones and Androids. It keeps you safe online, protects your privacy, and lets you browse the web quickly. You can even use it on all your devices and keep your browsing history and favorites synced up. Built on the same technology as Chrome, Microsoft Edge has additional built-in features like Startup boost and Sleeping tabs, which boost your browsing experience with world class performance and speed that are optimized to work best with Windows. Microsoft Edge security and privacy features such as Microsoft Defender SmartScreen, Password Monitor, InPrivate search, and Kids Mode help keep you and your loved ones protected and secure online. Microsoft Edge has features to keep both you and your family protected. Enable content filters and access activity reports with your Microsoft Family Safety account and experience a kid-friendly web with Kids Mode. The new Microsoft Edge is now compatible with your favorite extensions, so it’s easy to personalize your browsing experience. Download: Microsoft Edge (64-bit) | 193.0 MB (Freeware) Download: Microsoft Edge (32-bit) | 170.0 MB Download: Microsoft Edge (ARM64) | 188.0 MB View: Microsoft Edge Website | Release History Get alerted to all of our Software updates on Twitter at @NeowinSoftware
    • Yeah, when I saw that, I wanted to find the nearest nose. You can't find a good nose these days when you need one.
    • Anthropic launches Claude Fable 5, a state-of-the-art AI model that beats OpenAI's GPT-5.5 by Pradeep Viswanathan Back in April, Anthropic announced Claude Mythos Preview, a frontier model with state-of-the-art coding capabilities. Due to the cybersecurity implications that would occur due to the availability of such a powerful model, Anthropic made it available to only a select set of companies around the world. The company's plan was to prepare appropriate guardrails before releasing such a powerful model to everyone. Now, after nearly two months, Anthropic announced Claude Fable 5, its most capable AI model yet for general users. The company also announced Claude Mythos 5, the same underlying model as Fable 5, but with safeguards lifted, making it more suitable for selected cybersecurity and biology use cases. Claude Fable 5 sits a tier above its Opus models and it beats most other generally available models across areas including software engineering, knowledge work, vision, scientific research, and long-running autonomous tasks. To prevent model misuse, when Claude Fable 5 detects certain requests related to cybersecurity, biology, chemistry, or model distillation, the request will be routed to the Claude Opus 4.8 model. Anthropic claims that these safeguards trigger in less than 5% of sessions on average. However, for large organizations working on critical software, Claude Mythos 5 can be availed through Project Glasswing. Later, Anthropic has plans to expand access through a broader trusted access program. As you can notice in the benchmarks above, Fable 5 and Mythos 5 are state-of-the-art on most key AI benchmarks and they are well ahead of OpenAI's frontier model, GPT-5.5. For example, Fable 5 is the new state-of-the-art model for vision tasks. Also, Mythos 5 has the strongest cybersecurity capabilities of any model in the world. Claude Fable 5 and Claude Mythos 5 are priced at $10 per million input tokens and $50 per million output tokens, which is less than half the price of Claude Mythos Preview. Another big change is that Anthropic is making a change to the way they handle business customer data for both Fable 5 and Mythos 5 models. The company will now require 30-day retention for all traffic on both first- and third-party surfaces. Anthropic promises that it won't use the data to train Claude models, instead it will use it against complex and novel attacks. Claude Fable 5 is available today on the Claude API and consumption-based Enterprise plans. It is also included at no extra cost for Pro, Max, Team, and seat-based Enterprise customers from today through June 22. After that, users on those plans will need usage credits to continue using Fable 5, unless Anthropic extends the included access window based on capacity. Developers can access Fable 5 through the Claude API using the claude-fable-5 model name.
  • Recent Achievements

    • Week One Done
      rubentuben8 earned a badge
      Week One Done
    • Week One Done
      ARaclen earned a badge
      Week One Done
    • One Year In
      jojodbn earned a badge
      One Year In
    • One Month Later
      jojodbn earned a badge
      One Month Later
    • Week One Done
      jojodbn earned a badge
      Week One Done
  • Popular Contributors

    1. 1
      +primortal
      525
    2. 2
      PsYcHoKiLLa
      232
    3. 3
      +Edouard
      124
    4. 4
      ATLien_0
      88
    5. 5
      Steven P.
      83
  • Tell a friend

    Love Neowin? Tell a friend!