Remote Management and Monitoring tool - SimpleHelp - File Signature

Hunt Hypothesis

The hypothesis is that an adversary is leveraging the SimpleHelp RMM tool to establish persistence or command and control channels by exploiting its file signature for covert communication. SOC teams should proactively hunt for this behavior in Azure Sentinel to detect potential adversary use of 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 'SimpleHelp Ltd'
| summarize FirstSeen=min(Timestamp), LastSeen=max(Timestamp), 
    Report=make_set(ReportId), Count=count() by DeviceId, DeviceName

Analytic Rule Definition

id: b2a2dfb0-9941-47ca-96c3-936d8938923d
name: Remote Management and Monitoring tool - SimpleHelp - 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 'SimpleHelp Ltd'
  | 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_SimpleHelp_filesig.yaml)

False Positive Guidance

• Scenario: Legitimate SimpleHelp File Signature Update
  Description: A system administrator is performing a routine update to the SimpleHelp agent file, which is signed by the vendor.
  Filter/Exclusion: file.hash.sha256 == "known_good_hash_of_simplehelp_agent"

• Scenario: Scheduled Job for System Monitoring
  Description: The SimpleHelp tool is configured to run a scheduled job that collects system performance metrics as part of standard IT monitoring.
  Filter/Exclusion: process.name == "simplehelp.exe" AND event_id == "scheduled_task_event_id"

• Scenario: Admin Task – Remote System Configuration
  Description: An IT admin is using SimpleHelp to remotely configure a group of endpoints, such as deploying software or applying security policies.
  Filter/Exclusion: process.user == "domain_admin_user" AND process.name == "simplehelp.exe"

• Scenario: File Integrity Monitoring (FIM) Check
  Description: The SimpleHelp tool is being used to monitor file integrity on endpoints, which is a common security practice.
  Filter/Exclusion: process.name == "simplehelp.exe" AND event_id == "file_integrity_check_event"

• Scenario: Remote Support Session Initiated by Help Desk
  Description: A help desk technician is using SimpleHelp to remotely support an end-user, which is a legitimate use case.
  Filter/Exclusion: process.name == "simplehelp.exe" AND process.user == "helpdesk_user_account"