Google recently released a list of YARA detection rules for malicious variants of the legitimate Cobalt Strike penetration testing framework that are being used by hackers in the wild. Cobalt Strike is a commercial attack framework designed for red teams that has also been adopted by many threat actors, from APT groups to ransomware gangs and other cybercriminals.
Living off the land is a common tactic
The abuse by attackers of system administration, forensic, or security tools that are either already installed on systems or can be easily deployed without raising suspicion has become extremely common. The use of this tactic, known as living off the land (LOTL), used to be a telltale sign of sophisticated cyberespionage groups who moved laterally through environments using manual hacking and placed great value on stealth.