Just a heads up to all PHPBB users. If you haven't upraded to version 2.0.11 It is advisable to update as soon as possible. This is a critical update and there have been many forums that I know of that have been totally trashed by what PHPBB is calling the Highlight exploit.
I suffered an attack yesterday and had over 500 guests an hour, the exploit is being used in conjuction with the search engines, the search engine finds a site with an older version of the Forum and then sends out the virus that has killed many sites. The only recovery once hit, is to restore the forum from backup.
I and many others were hit with yesterdays attack and due to the updates we were able to survive it. There is also a code change to the config.php file that will kill these hits and not make your guest count jump.