Remote Management and Monitoring tool - MeshCentral - File Signature

Hunt Hypothesis

The detection identifies potential adversary use of MeshCentral, a remote management tool, to establish persistent remote access or command and control channels. SOC teams should proactively hunt for this behavior in Azure Sentinel to detect and mitigate advanced persistent threats leveraging RMM tools for long-term access and exfiltration.

KQL Query

let Time_start = now(-5d);
let Time_end = now();
//
DeviceFileCertificateInfo
| where Timestamp between (Time_start..Time_end)
| where Signer has 'meshcentral'
| summarize FirstSeen=min(Timestamp), LastSeen=max(Timestamp), 
    Report=make_set(ReportId), Count=count() by DeviceId, DeviceName

Analytic Rule Definition

id: 4837cef7-648e-42ab-96a5-3722910922a5
name: Remote Management and Monitoring tool - MeshCentral - File Signature
description: |
    Remote Monitoring and Management (RMM) programs are IT to manage remote endpoints. Attackers have begun to abuse these programs to persist or provide C2 channels.
    https://github.com/jischell-msft/RemoteManagementMonitoringTools
requiredDataConnectors:
- connectorId: MicrosoftThreatProtection
  dataTypes:
  - DeviceFileCertificateInfo
tactics: CommandAndControl
relevantTechniques: T1219
query: |
  let Time_start = now(-5d);
  let Time_end = now();
  //
  DeviceFileCertificateInfo
  | where Timestamp between (Time_start..Time_end)
  | where Signer has 'meshcentral'
  | summarize FirstSeen=min(Timestamp), LastSeen=max(Timestamp), 
      Report=make_set(ReportId), Count=count() by DeviceId, DeviceName

MITRE ATT&CK Context

• Tactic: CommandAndControl
• Technique: T1219 — T1219

References

• [Source Query](https://github.com/Azure/Azure-Sentinel/blob/main/Hunting Queries/Microsoft 365 Defender/RemoteManagementMonitoring/rmm_MeshCentral_filesig.yaml)

False Positive Guidance

• Scenario: Scheduled System Maintenance via MeshCentral
  Description: An admin uses MeshCentral to schedule routine system maintenance tasks, such as disk cleanup or patching, which may involve file operations that trigger the file signature detection.
  Filter/Exclusion: process.name IN ("task scheduler", "schtasks.exe") or process.parent.name IN ("meshcentral.exe")

• Scenario: Legitimate File Transfer via MeshCentral for Software Deployment
  Description: IT administrators use MeshCentral to deploy software updates or configuration files to endpoints, which may include file signature checks that match the detection rule.
  Filter/Exclusion: process.name IN ("meshcentral.exe") AND file.path IN ("C:\temp\updates", "C:\software\deploy")

• Scenario: User-Initiated Remote Desktop Connection via MeshCentral
  Description: A user connects to their own machine using MeshCentral for remote access, which may involve file operations or system monitoring that trigger the rule.
  Filter/Exclusion: user.name == "admin" OR user.name == "ITUser" OR process.name IN ("mstsc.exe", "remote desktop")

• Scenario: Log Collection and Analysis via MeshCentral
  Description: The IT team uses MeshCentral to collect system logs or performance data from endpoints, which may involve file access or monitoring that matches the rule.
  Filter/Exclusion: file.path IN ("C:\Windows\System32\logfiles", "C:\ProgramData\logcollector") or process.name IN ("logparser.exe", "eventvwr.exe")

• Scenario: Configuration Management via MeshCentral for Compliance
  Description: Admins use MeshCentral to push configuration changes or compliance policies to endpoints, which may involve file modifications or system monitoring that triggers the rule.
  Filter/Exclusion: `