What's cool about Ratiomaster's script is that it can catch any "base64_decode" injection in all directories - am I correct?
You can drop it in any directory and it will search it and all subdirectories.
Official tool is more user friendly and comprehensive, it looks in 'php', 'phtml', 'php3' for pattern. But it requires that you drop this tool in your forum folder.
Also trying to look something in database - not found anything on my site and it slightly suspicious, because i didnt touched database and if exploit does change database, then it means the backdoor is still there...
I dont suggest to run official tool on the whole site (on the forum only its probably OK), because it can corrupt one of your valid files .
I'd wait until official team fix those issues first.