Since the removal of GMs, most of the rule violation system is operated through external means - the report system and the bot detection tools, so there's no need for staff to log in to hand out punishments. Only on rare occassions has members of the Cipsoft team logged on and banned players in-game. I have a hard time finding an example but I remember seeing a Cipsoft member banning a dice bot in Thais once. Maybe someone else has more examples of this happening.
This is however most likely done by a Cipsoft member who is working with support, and not likely a CM, as this wouldn't be the typical work for a Community Manager. There's eleven departments at Cipsoft, 1 of them being Community Management - this is what a CM works with, and then there's the Support-department.
So to answer your question: No, CMs don't log in to ban people. The Cipsoft staff that deals with customer support have perhaps on rare occassions done so but very rarely since it would interfere with their automatic and external ways to deal with punishments.