Microsoft’s Digital Crimes Unit (DCU), cybersecurity software company Fortra™ and Health Information Sharing and Analysis Center (Health-ISAC) are taking technical and legal action to disrupt cracked, legacy copies of Cobalt Strike and abused Microsoft software, which have been used by cybercriminals to distribute malware, including ransomware. This is a change in the way DCU has worked in the past – the scope is greater, and the operation is more complex. Instead of disrupting the command and control of a malware family, this time, we are working with Fortra to remove illegal, legacy copies of Cobalt Strike so they can no longer be used by cybercriminals. We will need to be persistent as we work to take down the cracked, legacy copies of Cobalt Strike hosted around the world. This is an important action by Fortra to protect the legitimate use of its security tools. Microsoft is similarly committed to the legitimate use of its products and services. We also believe that Fortra choosing to partner with us for this action is recognition of DCU’s work fighting cybercrime over the last decade. Together, we are committed to going after the cybercriminal’s illegal distribution methods. Cobalt Strike is a legitimate and popular post-exploitation tool used for adversary simulation provided by Fortra. Sometimes, older versions of the software have been abused and altered by criminals. These illegal copies are referred to as “cracked” and have been used to launch destructive attacks, such as those against the Government of Costa Rica and the Irish Health Service Executive. Microsoft software development kits and APIs are abused as part of the coding of the malware as well as the criminal malware distribution infrastructure to target and mislead victims. The ransomware families associated with or deployed by cracked copies of Cobalt Strike have been linked to more than 68 ransomware attacks impacting healthcare organizations in more than 19 countries around the world. These attacks have cost hospital systems millions of dollars in recovery and repair costs, plus interruptions to critical patient care services including delayed diagnostic, imaging, and laboratory results, canceled medical procedures, and delays in delivery of chemotherapy treatments, just to name a few. Fortra and Microsoft’s investigation efforts included detection, analysis, telemetry, and reverse engineering, with additional data and insights to strengthen our legal case from a global network of partners, including Health-ISAC, the Fortra Cyber Intelligence Team, and Microsoft Threat Intelligence team data and insights. Our action focuses solely on disrupting cracked, legacy copies of Cobalt Strike and compromised Microsoft software. Microsoft is also expanding a legal method used successfully to disrupt malware and nation-state operations to target the abuse of security tools used by a broad spectrum of cyber criminals. Disrupting cracked legacy copies of Cobalt Strike will significantly hinder the monetization of these illegal copies and slow their use in cyberattacks, forcing criminals to re-evaluate and change their tactics. Today’s action also includes copyright claims against the malicious use of Microsoft and Fortra’s software code which are altered and abused for harm. More detailed information can be found on OUR FORUM.