Hi Stefan & welcome to the forum.
I've done a simple test with my EMC 8.0.2 - configure a alarm for the syslog event if a user logs in to my switch.
Here how the syslog event looks like...
And here my customer alarm...you'd need to match on the Syslog log manager and and then on the information text i.e. passed - in my test.
If it still doesn't work could you please open a new post so we'd separate it from the other ones and make sure to incl some screenshots of the configuration.
-Ron