Unable to remove a PC Checkup

I did not authorize the download of this product, not even as a bundle with an upgrade, in fact I have not performed any upgrades lately. The program does not appear in the control panel, so I can not remove it there. I downloaded the Norton removal tool which said it removed all Norton programs, the program is still there. Please tell me how to remove this program, (it is indeed malware despite the claims here the it isn't - I never authorized it's installation on my computer).