claudetools/projects/msp-tools/guru-scan

GuruScan

Multi-engine malware scan orchestrator for GuruRMM. Runs a sequenced chain of portable security scanners, captures all logs, and writes structured JSON results for downstream processing by the RMM agent.

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Deploy Layout

Path	Purpose
C:\GuruScan\	Base directory — module files, whitelist, state files
C:\GuruScan\downloads\	Scanner EXEs (populated by Download-Scanners.ps1)
C:\GuruScan\reports\	Per-scan zip archives
C:\ScanLogs\	Per-scan log folders (<HOSTNAME>-<YYYYMMDD-HHmmss>\)

The module files (GuruScan.psm1, GuruScan.psd1, scanners.json) live in the same directory as the launcher scripts (Invoke-GuruScan.ps1, etc.). This is typically C:\GuruScan\ or the RMM deployment path — wherever the scripts are placed.

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Scanner Chain

Scanners run in this order. Each stage hands off to the next regardless of findings.

#	Scanner	Category	Notes
1	RKill	process-killer	Kills malware-related processes before scanners run. Exit 1 = processes were killed (not a threat indicator).
2	AdwCleaner	adware	Removes adware, PUPs, and browser hijackers. Requires an interactive user session (GUI app; no headless/SYSTEM mode). Skipped automatically when running as SYSTEM with no desktop. To include AdwCleaner, dispatch via GuruRMM with context: user_session.
3	Emsisoft Command Line Scanner	antimalware	Two-step: NSIS installer extracts to C:\EmsisoftCmd\, then /update fetches latest definitions, then scans.
4	HitmanPro	antimalware	Cloud-assisted second-opinion scanner. Trial registry is reset before each run via Invoke-HitmanProTrialReset.

MSERT (Microsoft Safety Scanner) is excluded from the default chain — it is too slow for routine remediation runs. Add it back to scanners.json if needed.

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Exit Code Semantics

Scanner	Exit 0	Exit 1	Exit 2	Exit 3	Other
RKill	Clean run	Processes killed (not a threat)	—	—	—
AdwCleaner	Clean	Cleaned, no reboot needed	Cleaned, reboot required	Found but not cleaned (scan-only)	—
Emsisoft	Clean	Threats found/cleaned	Cleaned, reboot required	—	—
HitmanPro	Clean	Cleaned	Cleaned, reboot required	—	—
MSERT	Clean	Threats found/cleaned	—	—	Non-zero = threats
TDSSKiller	Clean	Threats found	—	—	—
Stinger	Clean	—	—	—	13 = threats

Reboot-required exit codes: AdwCleaner 2, HitmanPro 2, Emsisoft 2.

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Post-Scan Cleanup Lifecycle

When any scanner exits with a reboot-required code (exit 2), the following sequence runs automatically — no forced reboot, no temp user account:

1. Register-ScannerCleanupTask writes cleanup-state.json (scan ID + log path) to C:\GuruScan\.
2. Invoke-ScannerCleanup.ps1 is written to C:\GuruScan\.
3. A SYSTEM scheduled task (GuruRMM-ScannerCleanup) is registered with an at-logon + 30-minute delay trigger.
4. The scan completes and prints a message to reboot at your convenience.
5. After the next natural reboot and user login, the task fires 30 minutes later (silently, in the background as SYSTEM).
6. The cleanup script removes all scanner installation paths (C:\EmsisoftCmd, C:\AdwCleaner, C:\ProgramData\HitmanPro*, C:\GuruScan\downloads\), writes logs-ready.json for GuruRMM to pick up, and unregisters itself.

To run cleanup immediately without waiting (e.g. if the task was missed):

.\Invoke-PostRebootCleanup.ps1

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Headless / SYSTEM Behavior

• -Headless passes NoNewWindow to all scanner launches, suppressing UI windows. Use this when dispatching from an RMM agent that has no interactive desktop.
• Scanners with session0_compatible: false in scanners.json are automatically skipped when the module detects it is running as SYSTEM (Session 0). Currently: AdwCleaner. The result record shows SKIPPED (requires user session) rather than a failure.
• To run AdwCleaner via GuruRMM, dispatch with context: user_session so it runs in the active user's desktop session (requires a logged-in user on the target machine).

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Licensing

Scanner	License for MSP use
RKill	Free (BleepingComputer)
AdwCleaner	Free for personal and commercial use
Emsisoft Command Line Scanner	Free for personal and MSP remediation use
HitmanPro	Commercial license required. Each scan uses trial mode; Invoke-HitmanProTrialReset resets the trial window. Verify current licensing terms at https://www.hitmanpro.com before deploying at scale.

Always verify current licensing terms with each vendor before large-scale deployment.

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Stand-alone Usage

# Run all scanners in clean mode (default)
.\Invoke-GuruScan.ps1

# Detect only, then auto-remediate if threats found
.\Invoke-GuruScan.ps1 -ScanOnly -AutoRemediate

# Suppress scanner windows (RMM dispatch)
.\Invoke-GuruScan.ps1 -Headless

# View the latest scan results
.\Get-ScanSummary.ps1

# View with AI analysis (requires Ollama)
.\Get-ScanSummary.ps1 -AI

# Re-run clean pass against a prior scan
.\Invoke-Remediation.ps1 -LogRoot "C:\ScanLogs\DESKTOP-20260523-143000"

# Download/refresh scanner EXEs
.\Download-Scanners.ps1

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Module Usage

The launcher scripts are thin wrappers. Import the module directly for scripted/pipeline use:

Import-Module .\GuruScan.psd1

# Disk sink (default) — writes results.json + CSV + zip
Invoke-GuruScan

# RMM sink — returns result object to the pipeline, no disk writes
$result = Invoke-GuruScan -OutputSink RMM -Headless
if ($result.total_threats -gt 0) { ... }

# Remediation from a prior scan
Invoke-Remediation -LogRoot "C:\ScanLogs\DESKTOP-20260523-143000"

# Summary report
Get-ScanSummary -AI

# Manual scanner cleanup (normally runs via scheduled task)
Invoke-PostRebootCleanup

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Module Structure

guru-scan\
  GuruScan.psm1               # Core module — all helpers + exported cmdlets
  GuruScan.psd1               # Module manifest
  scanners.json               # Scanner definitions (single source of truth)
  Invoke-GuruScan.ps1         # Thin launcher -> Invoke-GuruScan
  Invoke-Remediation.ps1      # Thin launcher -> Invoke-Remediation
  Get-ScanSummary.ps1         # Thin launcher -> Get-ScanSummary
  Invoke-PostRebootCleanup.ps1 # Thin launcher -> Invoke-PostRebootCleanup (manual cleanup trigger)
  Invoke-ScannerCleanup.ps1   # Post-reboot cleanup script; copied to C:\GuruScan\ when reboot is needed
  Download-Scanners.ps1       # Downloads scanner EXEs from scanners.json URLs
  downloads\                  # Scanner EXEs (gitignored)