I built a Drupal site for an organization and handed over the keys a couple of years ago. Now I see that the forums are full of spam, and the version of Drupal is well out of date.
There is a bulk delete to delete the hundreds of fake logins that the spammers have created, and I've done that, but is there a way to bulk delete all the spam in the forums? As far as I can tell it takes about three or four steps just to delete a single spam topic, and there are hundreds of them.
Use a module to prevent spam, such as Akismet:
http://drupal.org/project/akismet
Haven't tried it myself, but it seems to fit your need.
It turns out that there is a bulk delete option, but it's under Content, not under Forums.