On the foundations of Dtrace the security specialists Tiller Beauchamp and David Weston created a tool for finding vulnerabilties in your code (or writting exploits, depends on your objectives). It uses the mechanisms of DTrace and extends them. As Internetnews writes in Blackhat: Dtrace a Rootkit:.
Sun's Dtrace application was developed primarily as a tool to help monitor functions on Solaris. According to a pair of security researchers at the Black Hat conference, you can also use Dtrace as the basis for a rootkit-like tool for offensive and defensive security operations.
Finding vulnerabilties and writting exploits are different sides of a special case of debugging code. And debugging is exactly the job, we´ve developed dtrace for. It was really obvious, that someone will use dtrace for such an usecase.