Impersonating IT support: how threat actors turn a remote session into enterprise-wide access
Microsoft details Teams IT-support impersonation campaigns deploying Node.js implants, AD reconnaissance, and WinRM lateral movement toward domain controllers.
Microsoft Threat Intelligence describes a human-operated campaign where attackers impersonate IT/helpdesk staff via Microsoft Teams external collaboration, talk users into granting remote sessions, and use RMM tools for interactive access. During the session they run PowerShell to silently install a malicious MSI that stages a portable Node.js runtime and obfuscated JavaScript implant for C2, executing follow-on payloads via rundll32. Operators then perform host and Active Directory reconnaissance, capture desktop screenshots, and pivot via WinRM on port 5985 to domain controllers and certificate authorities. The hands-on-keyboard chain, which can precede data theft and ransomware, blends into normal operations by relying on Teams, Quick Assist, msiexec, and Node.js; Microsoft shares hunting and mitigation guidance.
CISA tells operators to harden Siemens S7 PLCs. Here’s how to do it without disrupting production
CISA, NSA, FBI and other agencies warn of active targeting of internet-exposed Siemens S7 PLCs and urge patching, exposure removal and hardening.
Joint advisory AA26-231A from the NSA, CISA, FBI, Department of Energy and EPA warns that actors are actively targeting Siemens S7 PLCs using internet scanning, AI-assisted scripts and libraries such as Snap7 and python-snap7 over S7comm on TCP port 102. The advisory covers S7-200 through S7-1500 series controllers and recommends patching, removing internet exposure, access controls, monitoring and disabling unneeded services. Siemens states no new S7 vulnerabilities are involved, only misconfigurations addressed in existing ProductCERT guidance SSB-104599. The article details how to apply each measure without breaking production dependencies such as remote I/O, HMI links and diagnostics.
Schneider Electric Easergy, EcoStruxture, PowerLogic, and Saitel Products (Update A)
CISA updated ICSA-26-169-07: CVE-2026-4827 (CVSS 8.3) insufficient entropy enables session hijacking across dozens of Schneider Electric grid products; fixes available.
CISA republished advisory ICSA-26-169-07 (Update A) for CVE-2026-4827, CWE-331 insufficient entropy in session management, scored CVSS 8.3. Affected lines include Easergy MiCOM relays and C5, EcoStruxure Power Automation (EPAS-GTW, EPAS-UI, iPMFLS), EcoStruxure Power Operation, PowerLogic P5/P7/T300/T500, and Saitel DP/T150 RTUs, with dozens of fixed versions listed. Successful exploitation could enable session hijacking and unauthorized operations on systems in energy, chemical, critical manufacturing, and water sectors. Fixes are available; no exploitation is reported.
Hackers Impersonate IT Support on Microsoft Teams to Take Control of Employee PCs
Microsoft warns of a human-operated campaign where attackers pose as IT support in Teams to gain remote PC control and reach domain controllers.
Microsoft Threat Intelligence observed attackers abusing Microsoft Teams external collaboration to impersonate IT/helpdesk staff, persuading employees to grant screen control via Quick Assist or RMM tools. Operators deploy malicious MSI packages via silent msiexec, run encrypted JavaScript implants through portable Node.js, and persist via EdgeUpdate Run keys or Startup folder entries. The Node.js backdoor uses HTTPS long-polling C2, captures screenshots, enumerates Active Directory, and moves laterally over WinRM (TCP 5985) to domain controllers and certificate authorities. Initial access maps to MITRE ATT&CK T1566.003 (Spearphishing via Service); no Teams vulnerability is exploited.