Today, a bunch of new instances appeared in the top of the user count list. It appears that these instances are all being bombarded by bot sign-ups.
For now, it seems that the bots are especially targeting instances that have:
- Open sign-ups
- No captcha
- No e-mail verification
I have put together a spreadsheet of some of the most suspicious cases here.
If this is affecting you, I would highly recommend considering one of the following options:
- Close sign-ups entirely
- Only allow sign-ups with applications
- Enable e-mail verification + captcha for sign-ups
Additionally, I would recommend pre-emptively banning as many bot accounts as possible, before they start posting spam!
Please comment below if you have any questions or anything useful to add.
Update: on lemm.ee, I have defederated the most suspicious spambot-infested instances.
To clarify: this means small instances with an unnaturally fast explosion in user counts over the past day and very little organic activity. I plan to federate again if any of these instances get cleaned up. I have heard that other instances are planning (or already doing) this as well.
It's not a decision I took lightly, but I think protecting users from spam is a very important task for admins. Full info here: https://lemm.ee/post/197715
If you're an admin of an instance that's defederated from lemm.ee but wish to DM me, you can find me on Matrix: @sunaurus:matrix.org
Sometimes, security just means not being the low-hanging fruit.
Doing no captcha is like leaving the door open, hoping no-one breaks in, instead of at least closing the door (a closed door decreases chance of break in by near 100%, even if it's not locked)