Originally posted here by riya_here
Do any of you have any idea of the companies who actively deal in Penetration Testing?
Most major technical consulting firms will have some sort of offering or ability in this area, even if it's just a handful of consultants who can perform the evaluations with COTs or opensource tools. Some offer it as a service, with a standardized lab and scripted evaluations that are analyzed and reviewed by an analyst. It depends on what you want, and how much you are willing to pay.

I know for a fact that you can pay any of these companies to perform a PenTest (also known as External Vulnerability Assessment or EVA, although that term has broader meaning and scope than PenTest):

Symantec
IBM
VeriSign
Counterpane

You could also Google for Professional Penetration Testing Service and get a boatload of results. However, there's no telling what will rank highest...