Two ransomware groups abuse Microsoft’s Office 365 platform to gain access to target organizations

Two ransomware groups exploiting Microsoft 365 services and default settings to target internal enterprise users. Sophos researchers started investigating two distinct clusters of activity, tracked as STAC5143 and STAC5777, in response to customer ransomware attacks in November and December 2024. Threat actors used their own Microsoft 365 tenants and exploited a default Teams setting allowing […]