Potentially Unwanted Program.
Download and install Malwarebytes for Mac directly from the Malwarebytes website, accept no other download option.
Run it and follow any instructions it gives you.
DO NOT DOWNLOAD MACKEEPER.
Are you sure you are running a Macbook? They were discontinued in 2006 which would make yours, if it is one, a bit long in the tooth
Something called ProductUpdater shows up in my Activity Monitor as consuming 95-99% of CPU and draining my Powerbook battery rapidly. What is this and how can I stop it?