↳ Source GitHubRègle analytiqueMedium
Disable or Modify Windows Defender
Description
This detection watches the commandline logs for known commands that are used to disable the Defender AV. This is based on research performed by @olafhartong on a large sample of malware for varying purposes.
Note that this detection is imperfect and is only meant to serve as basis for building a more resilient detection rule. Make the detection more resilient, currently the order of parameters matters. You don't want that for a production rule.
See blogpost (https://medium.com/falconforce/falconfriday-av-manipulation-0xff0e-67ed4387f9ab?source=friends_link&sk=3c7c499797bbb4d74879e102ef3ecf8f) for more resilience considerations. The current approach can easily be bypassed by not using the powershell.exe executable.
Consider adding more ways to detect this behavior.
- Type de règle
- Scheduled
- Version
- 1.0.1
- Statut déclaré
- Available
- Fréquence
- 1h
- Période analysée
- 1h
- Déclenchement
- gt 0
Couverture MITRE déclarée
Sources déclarées
Métadonnées du fichier source. Aucune dépendance déduite du KQL.
Connecteurs
Types de données
Requête KQL
Requête originale, sans modification.
let defendertampering=dynamic(["Set-MpPreference -DisableRealtimeMonitoring $true","sc stop WinDefend","sc delete WinDefend","Set-MpPreference -DisableBehaviorMonitoring $true","Set-MpPreference -ExclusionProcess", "Set-MpPreference -ExclusionExtension dll","net stop security center"]);
DeviceProcessEvents
| where ProcessCommandLine has_any (defendertampering)
// If you have a lot of false positives coming from JetBrains, you can use the line below.
//| where InitiatingProcessFolderPath !startswith @"c:\program files\jetbrains\" and InitiatingProcessVersionInfoProductName !~ ("Android Studio")
Entités déclarées
Contenus associés
Liens établis à partir des identifiants déclarés et des manifests des solutions.
Traçabilité de la source
GitHubLes valeurs affichées proviennent des fichiers du dépôt Azure/Azure-Sentinel. Elles décrivent le modèle publié, pas la configuration de votre workspace.
- Commit
9800e51↗- Identifiant source
20d52a04-b5d8-402d-88e2-7929d12cbdcd
GSTEP / SUIVI DU CATALOGUE
Ajouté au catalogue : 16 sept. 2026 · 05:49 UTC
Dernier changement observé : 16 sept. 2026 · 05:49 UTC