Chinese Threat Actors Exploit ToolShell SharePoint Flaw Weeks After Microsoft's July Patch

Threat actors with ties to China exploited the ToolShell security vulnerability in Microsoft SharePoint to breach a telecommunications company in the Middle East after it was publicly disclosed and patched in July 2025. Also targeted were government departments in an African country, as well as...

Microsoft Links Ongoing SharePoint Exploits to Three Chinese Hacker Groups

Microsoft has formally tied the exploitation of security flaws in internet-facing SharePoint Server instances to two Chinese hacking groups called Linen Typhoon and Violet Typhoon as early as July 7, 2025, corroborating earlier reports. The tech giant said it also observed a third China-based...

Disrupting active exploitation of on-premises SharePoint vulnerabilities

July 23, 2025 update – Expanded analysis and threat intelligence from our continued monitoring of exploitation activity by Storm-2603 leading to the deployment of Warlock ransomware. Based on new information, we have updated the Attribution, Indicators of compromise, extended and clarified...