Hacker

[traceyham]

If after controlling the router and only allowing your Mac to connect with it there is still some strange activity going on, then something in your computer is sending the data, and it will be easy to find out what is going on.
Little Snitcher.

Thank you McGiord for the constructive help. I downloaded Little Snitch last night and this morning my speeds are back up to normal and all is quiet for the first time in weeks with no unknown MAC address connected to my router ... or devices I have turned off showing up in my connected clients. Coincidence? Who knows, but for now I have a decent connection.

 

[McGiord]

Thank you McGiord for the constructive help. I downloaded Little Snitch last night and this morning my speeds are back up to normal and all is quiet for the first time in weeks with no unknown MAC address connected to my router ... or devices I have turned off showing up in my connected clients. Coincidence? Who knows, but for now I have a decent connection.

Glad to know that you have it under control now.
Happy 2012 and keep it safe!