Received strange broadcast message that appeared to come from a server this

Novell Rules, it has too much power. Have a Happy NEW Year!!!

This sounds like someone playing on our network. NAs said it wasn't them.
Can anyone suggest where we can find out where this came from?

Broadcast is supposed to be turned off on our novell client. There is no
connection information, etc...
The command did not show up on the console or console log.

Any hacker tools that might allow someone to broadcast a message, etc....?

school district