MyBB Community Forums

not sure whats going on with this issue, everything has been fine since we launched the forum a few weeks ago. The issue started today (April 1st, and its not a prank :p). We migrated servers yesterday and used a backup of the sql tables provided by mybb and everything was fine, come today I go to login to my admin account and my password is changed, not only that but my usergroup has been changed as well.

now the users are also having this problem, what could possibly be going on? I've checked the admin logs and everything is fine there, no activity concerning users accounts being modified.

The forum in question is http://www.dragonnestplus.com/forum/

any help would be appreciated

Make sure your forum is not compromised? Because by default, there is no such system which does this. Secondly make sure you have no such password expiring and reset after 'x' days plugin installed.