Remote Management and Monitoring tool - BarracudaRMM - Network Connection

Hunt Hypothesis

The hypothesis is that an adversary is using BarracudaRMM to establish a covert network connection for command and control or persistence. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify potential C2 channels and mitigate advanced persistent threats leveraging legitimate RMM tools.

KQL Query

let Time_start = now(-5d);
let Time_end = now();
//
DeviceNetworkEvents
| where Timestamp between (Time_start..Time_end)
| where RemoteUrl has_any (
        'rmm.barracudamsp.com',
        'content.ivanti.com' // Backup solution used by Barracuda MSP
    )
    and InitiatingProcessVersionInfoCompanyName has_any (
        'Barracuda MSP',
        'LPI Level Platforms'
    )
| summarize FirstSeen=min(Timestamp), LastSeen=max(Timestamp), 
    Report=make_set(ReportId), Count=count() by DeviceId, DeviceName,
    RemoteUrl 

Analytic Rule Definition

id: 62263920-ab21-4fc6-84ce-00ca4360c091
name: Remote Management and Monitoring tool - BarracudaRMM - Network Connection
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:
  - DeviceNetworkEvents
tactics: CommandAndControl
relevantTechniques: T1219
query: |
  let Time_start = now(-5d);
  let Time_end = now();
  //
  DeviceNetworkEvents
  | where Timestamp between (Time_start..Time_end)
  | where RemoteUrl has_any (
          'rmm.barracudamsp.com',
          'content.ivanti.com' // Backup solution used by Barracuda MSP
      )
      and InitiatingProcessVersionInfoCompanyName has_any (
          'Barracuda MSP',
          'LPI Level Platforms'
      )
  | summarize FirstSeen=min(Timestamp), LastSeen=max(Timestamp), 
      Report=make_set(ReportId), Count=count() by DeviceId, DeviceName,
      RemoteUrl 

Required Data Sources

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_BarracudaRMM_netconn.yaml)

False Positive Guidance

• Scenario: Scheduled system updates via Barracuda RMM
  Description: The RMM tool may initiate outbound connections to download and install updates on managed endpoints.
  Filter/Exclusion: process.name IN ("update.exe", "msiexec.exe", "setup.exe") or check for known update URLs from Barracuda’s update servers.

• Scenario: Remote desktop session initiated by an admin using Barracuda RMM
  Description: An administrator may use the RMM tool to initiate a remote desktop session to troubleshoot an endpoint.
  Filter/Exclusion: process.name IN ("mstsc.exe", "rdp.exe") and check for known admin IP ranges or user accounts.

• Scenario: Automated backup job executed via Barracuda RMM
  Description: The RMM tool may trigger a scheduled backup job that connects to a backup server or cloud storage.
  Filter/Exclusion: process.name IN ("backup.exe", "vssadmin.exe") or check for known backup server IPs or domains.

• Scenario: Remote PowerShell script execution for system monitoring
  Description: An admin may use Barracuda RMM to run PowerShell scripts for system monitoring or diagnostics.
  Filter/Exclusion: process.name IN ("powershell.exe") with a filter on command-line arguments like "Get-EventLog" or "Get-Service".

• Scenario: Remote file transfer for software deployment via Barracuda RMM
  Description: The RMM tool may initiate file transfers to deploy software or configuration files to endpoints.
  Filter/Exclusion: process.name IN ("robocopy.exe", "xcopy.exe", "certutil.exe") or check for known deployment servers or file hashes.