For security teams on the front lines and those of us in the business of stopping cyberattacks and breaches, 2021 provided no rest for the weary. In the face of massive disruption brought about by the COVID-driven social, economic and technological shifts of 2020, adversaries refined their tradecraft to become even more sophisticated and brazen. The result was a series of high-profile attacks that rocked many organizations and, on their own, represented watershed moments in cybersecurity.