In September 2017, the world witnessed a massive supply chain attack on CCleaner, a popular utility tool. While 2.27 million users were affected, the true intent of the attack was far more sinister. Hidden within the chaos was a highly targeted espionage operation by APT41, surgically focused on 40 specific technology companies. Participants will delve into this complex scenario, tracing the steps of this notorious APT group and unveiling their covert objectives.