Suspicious Defendnot Antivirus Disabling Component Dropped in ProgramData (via file_event)

ATT&CK techniques

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects the multi stage campaign deploying the Defendnot tool which drops defendnot.dll and defendnot-loader.exe into ProgramData and injects into Taskmgr.exe to deregister Microsoft Defender. Creation of these named components indicates an attempt to blind endpoint protection. This precedes the RAT and ransomware stages.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange

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Malicious Windows Defender Root Exclusion via Add-MpPreference (via process_creation)

Suspicious Modification of Windows Hosts File

Malicious AMSI and ETW Bypass via In-Memory Patching (via ps_script)

Suspicious Defendnot Antivirus Disabling Component Dropped in ProgramData (via file_event)

Pivot detection · T1685 · 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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