CNet seems to be wrapping any software they host in their own installer, with their own revenue-producing add-ons.
Core Temp does come with an installer which sometimes gets flagged incorrectly by NOD, there were some other AV software at the beginning, but it has been dealt with.
The installer Core Temp now comes with may not look very trustworthy or professional from perspective of power users, but it is safe. It allows you to opt-out of the offers by clicking Decline.
Also, if interested you can get a standalone version (no installer), in a ZIP archive by clicking on "More downloads..."