---
name: reference_datto_edr_detection_behavior
description: How Datto EDR (azcomp4587) actually detects/reports, and AV-suppression gotchas — verified live on RMM-TEST-MACHINE
metadata:
  type: reference
---

Verified live 2026-06-25/26 on RMM-TEST-MACHINE (EDR agent `b98b3ba0-...`, group `[TEST] RMM-TEST-MACHINE`, org Arizona Computer Guru) via the `datto-edr` skill + `/rmm`.

**Alert `sourceType` taxonomy (how to tell WHICH engine fired):**
- `av` = Datto AV signature hit (e.g. `Eicar-Test-Signature`). On-access/RTP.
- `rule` = Datto **EDR** detection — reputation/analyst rule on the forensic scan (e.g. `Generic Malware (Reputation - High Severity)`, description "Malware detected by endpoint protection").
- Both land in the same `Alerts` collection and surface identically via `edr.py detections`.

**Datto EDR is reputation-based, NOT structural.** A synthetic "looks suspicious" artifact (Run-key/scheduled task launching hidden `-EncodedCommand` powershell) is collected by the forensic scan but scored BENIGN → no alert (powershell.exe is signed/clean). To get an EDR detection you need a real reputation hit: wire a known-bad file as the **executable of an autostart** (Run-key/scheduled task) so the survey collects + hashes it. EICAR-as-autostart works → high-sev `rule` alert. A loose file on disk is NOT scanned by the EDR forensic survey (it only walks execution/persistence artifacts).

**BUT behavioral rules DO fire on signed PowerShell** (unlike the reputation scoring above). Rules like **"Exfiltration Over HTTP Protocol" (T1041)** key on *runtime behavior* (outbound HTTP from powershell), not file reputation, so they alert HIGH on clean signed `powershell.exe` — and can carry an automated `isolate-host`/`kill-process` response. This routinely false-positives on GuruRMM automation (`gururmm-agent.exe -> cmd.exe -> powershell`). See [[project_edr_rmm_autoisolation_fp]].

**AV-suppression gotchas (to isolate EDR on an endpoint):**
- Datto AV is **tamper-protected**: `Stop-Service EndpointProtectionService2 -Force` is refused ("cannot be stopped"); can't disable from the endpoint. Supported path = console policy (AV disabled / path-exclusion) — console-only, like policy assignment.
- Disabling Datto AV in the policy **uninstalls** the AV component on the box (services `EndpointProtectionService`/`...2` go absent; `HUNTAgent` EDR stays). Platform `dattoAvEnabled` flips to False at the console first; the on-box apply lags a few minutes.
- Removing Datto AV makes **Windows Defender auto-reactivate** (Security Center turns it back on when no 3rd-party AV registered). Then Defender RTP quarantines EICAR AND its **AMSI blocks any PowerShell script containing the literal EICAR string** ("script contains malicious content"). Build EICAR from char codes so the literal never appears in the script; disable Defender RTP (or path-exclude) too.
- After testing: restore Defender RTP (`Set-MpPreference -DisableRealtimeMonitoring $false`) and re-enable Datto AV in the console policy.

Skill: [[reference_syncro_rmm_api_gui_only]] is the analogous "management is GUI/console-only" constraint. See `.claude/skills/datto-edr/`.
