Raphael Mudge
American developer of Armitage and Cobalt Strike, the red team tool that became as popular with criminals as with the people hired to imitate them.
In 2010 Mudge built Armitage, a graphical front end for Metasploit. Cobalt Strike followed in 2012, a commercial kit for simulating advanced attackers. Its implant, Beacon, talks quietly to a C2 server and can shape its traffic to profiles that mimic legitimate services, which was the whole point: defenders should get to train against something realistic.
Realistic it was. Cracked and leaked copies found their way to ransomware crews and state actors, and Beacon became one of the most common finds in incident response. Mudge sold his company, Strategic Cyber, to HelpSystems in 2020. Before all that he had written the After the Deadline grammar checker.