Good move on their part, tbh. Habang di pa resolved yung situation it's prudent that instances be put offline muna. From one of the comments in this thread have said:

From the few bits I’ve read, it sounds like the issue is spreading through comments and involves the markdown parser. This needs dev intervention, not just admins.

and from the clarification made after I asked:

https://i.imgur.com/uqW3P8o.png

It may well be that the lemmy.world admin account was compromised as a result of the hack, rather than to make it happen.

Apparently Memmy is immune to this, not sure about other apps. Someone else advised staying loggged out, and maybe be prepared to change your password after it's resolved.