I just found an unknown user account called admin belongs to the administrative group. Seems like some one has got into my server and created the account.
I am the only user and i use remote desktop to access to my server most of the time. The password i use were quite lengthy about 15 alpha numeric characters.
My questions is,
1) How did he break into my server and created a new user?
2) I have deleted the unknown account, changed my password and restarted the server. What should i do to further secure the server?