The 2021 Round 4 MITRE ATT&CK evaluations focused on Wizard Spider and Sandworm, threat actor groups known to target large corporations and healthcare institutions. Wizard Spider is largely a financially motivated ransomware crime group conducting campaigns since 2017. The Sandworm team is a Russian Threat group that has been linked to the 2015 and 2016 targeting of Ukrainian electrical companies and the 2017 NotPetya attacks.
Article Link: Webinar April 7th: 2021 MITRE ATT&CK Evaluations Explained