XMPP Service Operators - 2021-01-18

Hello

I'm getting spam from jabber.freenet.de

Their site is only in german

The same spam service

https://clck.ru/SZPyZ

mimi89999: If that .ru link is itself from the spam please in the future use hxxp to prevent misclicks

OK. Sorry.

octagon: No, not broken. mod_block_strangers - this is still the only effective method of fighting spam and flooding. It can be enhanced with captcha, which can create an impenetrable borrier.

impenetrable for people who want to talk to you, for sure!

Martin, Spammers are two people. It's even funny that this supposedly creates a problem.

Ge0rG, Reconfigure your client so that he sent the subscription along with the message and then it will not create a problem for you.

Ge0rG, Prosody doesn't have a module similar to mod_block_strangers?

404.city: most clients don't support that. All spammers send a subscription request ahead of actual messages

404.city: I don't care and I don't know.

404.city: it's the wrong approach

404.city: 99% of xmpp spam follows a simple pattern that allows identifying and blocking the bots.

What do you mean?

> 404.city: Martin, Spammers are two people. It's even funny that this supposedly creates a problem.

Is there a bogofilter module?

Martin, The same people are in the back contacts for buying spam.

Ge0rG, How much do you think using subscriptions would reduce the amount of incoming spam?

404.city: I don't understand the question

100% of spam is subscription request, then message

blocking just the message doesn't solve the problem

Ge0rG, The main goal of spammers is to deliver a message. How efficiently do you think messages with blocked strangers would be delivered?

404.city: there are two numbers to consider: false positives and false negatives.

you can block 100% spam by disabling all messaging

but then you also have a 100% false positive blocking rate

with mod_block_strangers, you exclude people who don't want to share presence with you, and you block people who can't solve captchas

If we block all messages, we will block all spam messages

404.city: You are aware of creep.im landing on the blocklist as we were not able to reach them due to mod_block_strangers + captcha?

Let's make mod_block_all

Exactly. So let's disable s2s and call it a day.

Martin: there will still be local spam bots

Then also disable c2s and you also blocked all spammers on your server.

Martin, but websockets!

Just pull the network cable on your server. That should be the ultimate spam fighting solution.

Martin, Yes, the captcha module has a bug so it is not usable right now.

`ifconfig eth0 down`

Ge0rG, that’s so 90ies! `ip link set eth0 down` please.

OK seriously is mod_block_strangers broken or not?

Ge0rG, Why do we need messages from strangers at all? 99% of these messages are flood or spam ....

octagon, captcha broken, modules no

I spent 30mins testing/playing with mod_block_strangers and it seems very unreliable.

404.city: I wrote my own captcha script

404.city: see above. "you exclude people who don't want to share presence with you"

octagon, captcha is other modules

octagon: do share ;)

Licaon_Kter: https://github.com/divestedcg/sbnr/blob/master/get_captcha.php

the meat is here https://github.com/divestedcg/sbnr/blob/master/sbnr/captcha.php GPLv3, requires PHP

octagon: this is integrated in a website? Would not show on IBR?

Licaon_Kter: nah I made a script for ejabberd that curls the image. It works just fine for ibr. You can try it on my server if you have my jid

Thanks

The problem with receiving spam is incorrect access rights. Strangers can send spam, so there is no way to protect yourself from spam as long as strangers can send anything.

404.city: everyone is a stranger until you say they ain't

The combination of the module for blocking messages from strangers with limiting the number of subscriptions sent, gives the desired result. One spammer cannot send more than a dozen messages from one account.

404.city: share the subscription ejabberd config part

404.city: you can't enforce number of subscriptions on *remote* servers

404.city: and IBR is cheap. spammers are registering thousands of accounts