It's not clear to me what was used here. Journalists haven't been very good at reporting this stuff and can't be relied on to understand the difference between MD5 (a cryptographic primitive intended to be very fast, and thus unsuitable for password hashes) and PHK-MD5 (Poul-Henning Kamp built a crypt scheme that uses many iterations of MD5 with salt, it was commonly used on Unix systems around the turn of the century)
Because this was specifically forum software I'm tempted to conclude that it was some simplistic MD5(salt + password) scheme of the sort used in several popular PHP forum programs. But it's by no means impossible to arrange to use PHK-MD5, either from PHP or from other popular web forum platforms.
PHK-MD5 isn't perfect, but it would put a serious crimp on attempts to reverse non-trivial passwords out of their hash, buying people time to hear about the problem and do something about it.
If this was off-the-shelf forum software we can probably determine for ourselves. After a good start a few years back, it seems forums and particularly PHP forums became rather complacent and most haven't ever got beyond adding some salt to reduce exposure to rainbow tables. So there certainly are products out there which still do MD5(salt + password) or SHA1(salt + password) or other things that should have been laughable forty years ago.