Has My Mac/Network Been Compromised?

[BenEndeem]

I noticed an odd server in the left hand column of Finder, seeing as I've not got a PC connected to the network I chose to take a closer look.

According to my router's log, a new IP (...2.7) logged in around the same time, so I assume someone has managed to crack my WPA password (considering it's random, that might show serious effort and intent was involved) or there's a blindingly obvious innocent explanation that I'm not seeing.

Due to this happening, I started to secure the network, but when I tried to turn off File Sharing on my iMac I was given a warning that other users may be logged in.

Could this mean that someone could have cracked both my WPA password and my iMac's password (different, but again random letters and numbers) or would it just say that even if they just got as far as the Drop Box?

Any help would be appreciated, thanks.

 

[BlueRevolution]

Yeah, even if they'd connected as a guest, you'd get the same notice. It doesn't necessarily mean that your Mac has been compromised. It does sound like someone unauthorized has gained access to your network, though.

 

[msevild]

There was another post on this forum with the same issue dealing with the other computer showing up in the sidebar. The user emeryemery explains it very nicely. Here is the link below. Check it out.
https://forums.macrumors.com/threads/558941/

 

[BenEndeem]

Thanks for the replies, I'm glad it was nothing serious.