Hey there Infern0, welcome to BleepingComputer.
Sorry for the delay in the reply.
This is a SID
, which stands for Security Identifier
and is used within NT/2000 as a value to uniquely identify an object such as a user or a group.
"The SID assigned to a user becomes part of the access token, which is then attached to any action attempted or process executed by that user or group. If a duplicate
SID did exist then all users with this SID would authenticate as what would be seen as the same user. It is possible for cloned machines to have the same SID, which would be seen by the authentication mechanism as the same machine. The SID under normal operation will be unique and will identify an individual object such as a user, group or a machine."
In simple terms Windows uses SIDs instead of usernames. For example, if you double-click a folder, Windows checks whether your SID is allowed to access it; it doesn't use your username.
You can read more about this at the link below:http://www.webopedia.com/TERM/S/SID.html