"Sanger's description of how Mandiant obtained some of the evidence underlying APT1 has resulted in a serious mischaracterization of our investigative efforts,a the cyber security firm said. "Specifically, Sanger suggests our investigators reached back through the network to activate the cameras on the hackers' own laptops. We did not do this, nor have we ever done this. "To state this unequivocally, Mandiant did not employ ahack back' techniques as part of our investigation of APT1, does not 'hack back' in our incident response practice, and does not endorse the practice of ahacking back," FireEye added. Mandiant's APT1 work is seen as a turning point among private cybersecurity reports.