They are prebaked rootkits. They're marketed as such and I think they never pretend otherwise. The truly sad thing is the amount of people that still send money to people who knowingly compromise their entire machine. Then they are thankful for it.

DRM is typically sold by a third party vendor. It is typically not effective against software pirates.

You are overstating its use, however.

I was thinking of the Sony rootkit, and the Starforce and VAC exploits.

The Sony toolkit debacle was its own thing. In addition, that rootkit was on music CDs.

I worked for a game division of Sony at the time, and we were furious at the mothership for that incident.