STAC5143 and STAC5777: Russian Hackers Exploiting Microsoft Platforms

Two Russian cybercriminal groups—STAC5143 and STAC5777—are at the forefront of a new wave of attacks exploiting Microsoft Teams and other Office 365 tools. From email bombing to impersonating IT support, their tactics are both sophisticated and dangerous. This blog dives into their methods, their connections to ransomware campaigns, and the broader implications for organizations using collaboration platforms. Learn how to mitigate risks by disabling unnecessary features, training employees, and staying vigilant against these increasingly common attacks.