Microsoft Revokes 200 Fraudulent Certificates Used in Rhysida Ransomware Campaign

Microsoft on Thursday disclosed that it revoked more than 200 certificates used by a threat actor it tracks as Vanilla Tempest to fraudulently sign malicious binaries in ransomware attacks. The certificates were "used in fake Teams setup files to deliver the Oyster backdoor and ultimately deploy Rhysida ransomware," the Microsoft Threat Intelligence team said in a post shared on X. The tech