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Comment by throwaway99210 | Hacker News Reader

> E.g. a large fai2ban rule to just ban anything that attempts to HTTP GET /admin.php or /phpmyadmin etc, even just once, gets rid of almost all nefarious bot traffic.

unfortunately fail2ban wouldn't even make a dent in the attack traffic hitting the endpoints in my day-to-day work, these are attackers utilizing residential proxy infrastructure that are increasingly capable of solving JS/client-puzzle challenges.. the arms race is always escalating

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we see the same thing, also with a financial company, the most successful strategies we’ve seen is making stuff like this extremely expensive for whoever it is if we see it, and they stop or slow down to a point it becomes not worth it and they move on. sometimes that’s really all you can do without harming legit traffic.

Such a rule is a great way to let malicious users lock out a bunch of your legitimate customers. Imagine if someone makes a forum post and includes this in it:

  [img]https://example.com/phpmyadmin/whatever.png[/img]

That would be in the body of the request. OP is talking about URLs in the actual request, which is part of the header.

While I don't have experience with a great number of WAFs I'm sure sophisticated ones let you be quite specific on where you are matching text to identify bad requests.

As an aside, another "easy win" is assuming any incoming HTTP request for a dotfile is malicious. I see constant unsolicitied attempts to access `.env`, for example.

When legitimate users viewed that forum post, their browsers would, in the course of loading the image, attempt to HTTP GET /phpmyadmin/whatever.png, with that being the URL in the actual request in the header.

A lot of modern standards rely on .well-known urls to convey abilities, endpoints, related services and so on.

In my case, I never run anything PHP so I'll just plain block out anything PHP (same for python, lua, activedirectory etc). And, indeed, .htaccess, .env etc. A rather large list of hardcoded stuff that gets an instant-ban. It drops the bot-traffic with 90% or more.

These obviously aren't targeted attacks. Protecting against those is another issue alltogether.

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