Malicious PowerShell Download of FortiEndpoint Patch Masquerade via EKZ Stealer

ATT&CK techniques

Execution → C2

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1105Ingress Tool Transfer
Exfiltration
Impact

What it detects

This rule detects PowerShell using WebClient DownloadFile to retrieve a payload named FortiEndpoint_Patch.exe into ProgramData. This masquerade is used after exploitation of Fortinet CVE-2026-35616 to stage the EKZ Stealer while posing as a security patch. Downloading a fake endpoint patch via PowerShell indicates active post-exploitation tooling.

Reporting behind it

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Malicious PowerShell Download of FortiEndpoint Patch Masquerade via EKZ Stealer

Pivot detection · T1059.001 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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