huntrule

FortiGate SSL VPN Settings Edited

Flags FortiGate VPN SSL settings being edited, which may indicate changes to SSL VPN access or authentication configuration.

FreeReviewedSigma · Medium · v2
Product
fortigate
Service
event
Author
Marco Pedrinazzi (@pedrinazziM) (InTheCyber) (SigmaHQ), DRL 1.1
Published
2025-11-01
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Initial Access → Persistence

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags FortiGate events where SSL VPN settings are edited, specifically changes under vpn.ssl.settings. Attackers may modify SSL VPN authentication-related configuration to establish or maintain remote access persistence. It relies on FortiGate event telemetry capturing an Edit action and the targeted configuration path.

Reporting behind it

Related detections9 linkedT1133 — drag to rearrange
SplashTop Network
Suspicious SoftEther VPN Hamcore Config Written to ProgramData (via file_event)
SplashTop Process
AnyDesk Network
OpenCanary RDP New Connection Attempt on Application Logtype 14001
ArcSOC.exe Creates Suspicious Script/Executable Files on Windows
FortiGate: Addition of VPN SSL Web Portal via Event Logs
Windows Process Creation: GoAnywhere child command execution indicating possible MFT exploitation
TeamViewer Remote Session Startup Command Execution on Linux
FortiGate SSL VPN Settings Edited
Pivot detection · T1133 · 9 related

Changelog

v2
  1. v2
    Candidate ingested via manual entry.2026-07-31
  2. v1
    No changelog recorded for this version.2026-07-30

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