It is quite certainly hostile... All the accounts I found are registered today.

darkmage84764
darkmage35966
darkmage91263
darkmage83385
darkmage23515
darkmage69131
darkmage31394
....

Between 2 reportings, there must be 60 seconds and the forum is full with this and I wanted to make someone aware of this.

You can use the "Report" button of the forum.
However, I've already done this earlier today for the
"Off-Topic » How did you end up here?" thread. It's not necessarily a
hostile "user", but maybe a hacked user account.