Since 26th September there have been 114 new members, all with very suspicious usernames, just click on memberlist & sort by descending, notice they are all female & all profiles contain links to very questionable websites.
21 more of them registered since midnight last night.
For my forum I use a website called stop forum spam to check new members, this site has a database of all known spammers usernames, emails and IP addressses, & I checked some of these new members on this database & quite a few of them are listed as reported spammers.
None of them have posted anything yet though or even logged into the forum.