Marcus Hutchins (MalwareTech)
termsecurityhacking
The young British researcher who stopped WannaCry in May 2017 by noticing an unregistered domain in the malware and buying it for about ten dollars - which turned out to be the worm's kill switch, halting a global outbreak within hours.
Three months later he was arrested in Las Vegas leaving DEF CON, charged over banking malware he had written years earlier as a teenager. He pleaded guilty, and in 2019 a judge sentenced him to time served, explicitly weighing what he had since done for the world against what he had done as a kid. The arc - accidental hero, defendant, and now respected researcher - is the most modern version of the field's oldest story, and it is why the community argues so hard about second chances.
Also known as: malwaretech, wannacry killswitch, kronos case