Half a centaur
Ignoring them is just asking for the forums to get flooded with virus filled links that gullible kids will click on. While preventing them is probably impossible, getting rid of their links is important.And there really isn’t much anyone can do as these bots tend to find ways around measures trying to prevent them from being on the site. It’s probably better to just ignore them
That being said, like Pokefan said, they definitely have an active time, I see them a lot late at night. Are there any mods that are available at around that time that can quickly do a sweep around the bots active hours to at least help prevent them a little quicker? Or would preventing links help (until you've been on the site for a certain time/certain amount of posts or something)? Minimize the click through rate by making it harder to access their sites. Anyone who is capable of of getting a link out of a bot message would probably be smart enough to know it's dangerous. It won't solve the bot issue entirely, but it should at least prevent younger kids from seeing a blue link and absentmindedly clicking it.