We have a number of instances of Event ID 5723 Source: NETLOGON on one of our DC's with Win Svr 2008 installed (see below). Although the pc in the event does not belong to our network and never did. I work for a financial organisation and security is as tight as it can be regarding physical access to our main office so I'm assuming this access attempt was made remotely. Please, can you help me out here on how this could have happened? We don't have wifi on our network so I'm a little baffled here. Please advise.