this post was submitted on 20 Jun 2023
68 points (98.6% liked)

Lemmy

12568 readers
2 users here now

Everything about Lemmy; bugs, gripes, praises, and advocacy.

For discussion about the lemmy.ml instance, go to !meta@lemmy.ml.

founded 4 years ago
MODERATORS
nutomic@lemmy.ml
68
PSA: Many Lemmy instances are currently experiencing massive automated sign-ups (bots)! If you run an instance with open sign-ups, please read! (lemm.ee)
submitted 1 year ago* (last edited 1 year ago) by sunaurus@lemm.ee to c/lemmy@lemmy.ml
63 comments fedilink hide all child comments
 

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:

  1. Close sign-ups entirely
  2. Only allow sign-ups with applications
  3. 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.

you are viewing a single comment's thread
view the rest of the comments
[–] freeskier@centennialstate.social 1 points 1 year ago* (last edited 1 year ago) (2 children)

Looks like my instance got hit with a bot. I had email verification enabled but had missed turning on captcha (captcha enable should be up with enabling email verification settings). The bot used fake emails so none of the accounts are verified, but still goes towards account numbers. Is there really any good way to clean this up? Need a way to purge unverified accounts or something.

[–] sunaurus@lemm.ee 1 points 1 year ago (1 children)

How comfortable are you with SQL? You can see all unused verifications in the email_verification table. You should be able to just delete those users from local_user, and then update your user count with the new count of the local_user table in site_aggregates.user (where site_id = 1)

[–] voldern@lemmy.ml 3 points 1 year ago

Thank you for proactively contacting me regarding this @sunaurus@lemm.ee. I've had this issue on my https://feddi.no instance, but I have added a captcha and registration applications now. Hopefully it will alleviate some of the problem.

All of the bots accounts seems to have a number in their email so I manually looked through the list of users in email_verification that contained numbers in the email to look for false positives:

select * from email_verification where email ~ '[0-9]+';

before running

delete from local_user where id in (select local_user_id from email_verification);

to delete the users.

By suggestion from @sunaurus@lemm.ee I updated site_aggregates to reflect the new users count on the instance:

UPDATE site_aggregates SET users = (SELECT count(*) FROM local_user) WHERE site_id = 1;.