SpamAssassin VS crowdsec

spamassassin or rspamd or ASSP. All very good. Spamassassin just works, but you need to feed it a good cohort of spam and ham (about 1000 messages each). Most people only send it the spam which will then bias it quite a bit and not have it classify spam as spam unless it's the worst of the bunch. Spamassassin is a filter for your mail server. rspamd is the same idea. ASSP is highly configurable and a proxy.

https://spamassassin.apache.org/ ?

I'm currently looking into using a Bayesian spam filter like Bogofilter or Apache Spamassassin to help out. I'd run the contents of my Contact Us form through the filter after the initial validation, and if the contents are below my spam threshold, I would actually send out the contact us request.

Avoid it. Apache's SpameAssassin flags several TLDs including .xyz as 'suspicious' nTLD[1].

[1]: https://github.com/apache/spamassassin/blob/trunk/rulesrc/sa...

The famous spam filter SpamAssassin. Score: -0.6. A score below -5 is considered spam. -0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid This rule is automatically applied if your email contains a DKIM signature but other positive rules will also be added if your DKIM signature is valid. See immediately below. 0.1 DKIM_VALID Message has at least one valid DKIM or DK signature Great! Your signature is valid 0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain Great! Your signature is valid and it's coming from your domain name 0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.001 HTML_MESSAGE HTML included in message No worry, that's expected if you send HTML emails 0.001 RCVD_IN_MSPIKE_H2 Average reputation (+2) 23.83.209.151 listed in wl.mailspike.net -0.001 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.001 SPF_PASS SPF: sender matches SPF record Great! Your SPF is valid -0.01 T_KAM_HTML_FONT_INVALID Test for Invalidly Named or Formatted Colors in HTML -0.644 URIBL_SBL Contains an URL listed in the SBL blocklist -0.1 URIBL_SBL_A Contains URL\'s A record listed in the SBL blocklist

Maybe you updated spamassassin in the process? Because it looks like they have a list of "spammy TLDs" and .site is in it.

To detect whether incoming emails are malicious, mail servers also use spam scanners, such as Apache's popular SpamAssasin. The internal workings of these spam scanners can be somewhat complicated (involving Naive Bayes Classifiers on trained, large datasets, for the curious), but the primary takeaway is that these classification systems typically assign a numerical point value to an incoming email to determine the validity of the message. The higher the score, the more likely that the email is spam. For reference, the ISP Optimum states the following regarding their spam filtering:

Hey we actually built the second part as a product. Its a modern revamp of fail2ban combined with crowdsourcing aspect to deliver an up-to-date blocklist of active threats. You can check it out at https://github.com/crowdsecurity/crowdsec

Today we are pleased to announce the launch of CrowdSec Engine 1.5 - this is a huge milestone for the project and one that would not have been possible without the help of this community. You can read see the full change log over on GitHub here https://github.com/crowdsecurity/crowdsec/releases

wget https://github.com/crowdsecurity/crowdsec/releases/latest/download/crowdsec-release.tgz server:> tar xzvf crowdsec-release.tgz https://github.com/crowdsecurity/crowdsec/releases/latest/download/crowdsec-release.tgz server: > tar xzvf crowdsec-release.tgz server:> cd crowdsec-v* && sudo ./wizard.sh -i

This tool crowdsec.net is really interesting to mitigate and enact defense systems for different scenarios.

CrowdSec is licensed under MIT open source license, you can find a copy of the text here: “Copyright 2020, CrowdSec SAS (http://crowdsec.net), Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.” That’s all there is to it. Like in the case of Debian, you can do anything you want with it, for free, period. You just need to embed this license when you redistribute the product.

You should check out https://crowdsec.net. More advanced, uses crowdsources cti to block attacks even before they happen. Also both nginx and captcha is supported. Disclaimer: I am head of community. Visit /r/CrowdSec or our Discord at https://discord.gg/crowdsec if you have questions :-)

Do I need something like crowdsec, or is WireGuard secure enough on its own?

Before falling too much in love with Fail2Ban try taking a look at https://crowdsec.net. Similar functionality but way more advanced (but easier to configure). New project that leverages the power of the crowd and shares information of attacks among users so they help each other out protecting themselves.