So recently I have had a few issues with my iMac desktop supposedly being hacked into. I did take it to an Apple Store where they had fixed the problem I thought (was quite detailed). I recently returned from having my iMac fixed and free of spyware with Yosemite installed. Last night I had been reinstalling wow onto my Mac with my firewall enabled and a secure wpa2 wireless hidden address with Mac address requirements for connection only enabled. Then out of the blue I get a prompt message on my Mac asking me to approve of an IP address connection through my network. Thinking it was something to do with my wow download I clicked accept - it was an IP address. However I have recently opened console on my iMac and thought many commands on the framework looked odd. I feel that something is also leeching my network speed. Could someone please help me in deleting this IP address from my firewall or deleting it from accessing my computer. Will reinstalling and deleting the operating system erase the IP address from my computer and firewall. It does not look to be showing up on the firewall.