We use Netragard to act as our White Hats. They are very good and cost effective. Before you select a vendor, do yourself a favor and talk with them. They did what they said they would do, when they said they would do it and at an agreed price. All work was performed remotely and all deliverables were electronic, including an executive summary and detailed analysis for my Engineering staff. They even went so far as to help us determine best practices, so as to mitigate our exposure. I couldn’t be happier with them.