Seattle-based stealth security startup Icebrg.io, started by two former National Security Agency employees, has raised $2.5 million in seed financing led by Madrona Venture Group, with participation from Formation 8, among other investors. The company is still in stealth mode, and all they are saying is that are working in the network security space.

Icebrg is founded by William Peteroy and Josh Carlson. The two met in Microsoft’s Security Response Group, said the company in a statement.  Icebrg says it has already deployed their technology in Fortune 200 companies which are increasingly finding themselves the target of attacks by professional hackers.