Is 'xhost local' (no colon) allowing malicious access?

I'm setting up a new system and need to grant the root user authority to access the nonroot user's X display in order to run GUI utilities. I used the xhost command for this as follows, but ***mistakenly*** leaving off the colon suffix seems to have allowed access to the remote server lb.usemaxserver.de... nonroot@host2:~ xhost - access control enabled, only authorized clients can connect nonroot@host2:~ xhost local local being added to access control list nonroot@host2:~ xhost access control enabled, only authorized clients can connect INET:lb.usemaxserver.de INET:localhost I've used the following to remove it... nonroot@host2:~ xhost -INET:lb.usemaxserver.de lb.usemaxserver.de being removed from access control list Am I interpreting this correctly? If so, how did lb.usemaxserver.de setup something so that local links to that addess? Does this require there to be some malicious configuration or software already on my system? If so, any suggestions for where to look?