The RTE Editor and the Basic Text Editor both use the same security filters. It would not matter if you had the
RTE Editor or the Basic Text Editor enabled if a spammers wants to post spam posts in your forum it would be the same under each editor.
The page below has information on reducing spam in your forum:-
If you upgraded to version 9.74 it would auto detect iPhones, iPads, and Android devices and switch the RTE Editor off for these devices allowing them to post.
If you upgraded to version 10 then in addition to the above you also have a spam filter, so you can configure the spam filter to reject posts with 'Ugg' or other words written in them. You can also configure the starting group for new members to not allow links, signatures, and images, which greatly reduces spam.