ToolShell

Pierluigi Paganini August 01, 2025
ToolShell under siege: Check Point analyzes Chinese APT Storm-2603

Storm-2603 group exploits SharePoint flaws and uses a custom C2 framework, AK47 C2, with HTTP- and DNS-based variants named AK47HTTP and AK47DNS. Check Point Research is tracking a ToolShell campaign exploiting four Microsoft SharePoint flaws, linking it to China-nexus groups APT27, APT31, and a new cluster, Storm-2603. The researchers pointed out that Storm-2603’s goals remain […]

Pierluigi Paganini July 23, 2025
Microsoft linked attacks on SharePoint flaws to China-nexus actors

Microsoft linked SharePoint exploits to China-nexus groups Linen Typhoon, Violet Typhoon, and Storm-2603, active since July 7, 2025. Microsoft confirmed that China-linked groups Linen Typhoon, Violet Typhoon, and Storm-2603 exploited SharePoint flaws for initial access as early as July 7, 2025. “As of this writing, Microsoft has observed two named Chinese nation-state actors, Linen Typhoon […]

Pierluigi Paganini July 22, 2025
SharePoint under fire: new ToolShell attacks target enterprises

While SentinelOne did not attribute the attack to a specific threat actor, The Washington Post linked it to China-nexus acors. On July 19, Microsoft confirmed active exploitation of a zero-day vulnerability, tracked as CVE-2025-53770 in on-prem SharePoint Servers. The IT giant issued emergency patches for SharePoint Subscription Edition and 2019, with 2016 updates pending. Microsoft […]

Pierluigi Paganini July 21, 2025
Microsoft issues emergency patches for SharePoint zero-days exploited in “ToolShell” attacks

Microsoft patched an exploited SharePoint flaw (CVE-2025-53770) and disclosed a new one, warning of ongoing attacks on on-prem servers. Microsoft released emergency SharePoint updates for two zero-day flaws, tracked as CVE-2025-53770 and CVE-2025-53771, exploited since July 18 in attacks dubbed “ToolShell.” Both vulnerabilities only impact on-premises SharePoint Servers, threat actors could chain them for unauthenticated, […]