Detects sample mentioned in the Dubnium Report

Hunt Hypothesis

The hypothesis is that the detected sample is associated with the Dubnium Report, indicating potential adversarial activity linked to known malicious campaigns. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate early-stage threats tied to sophisticated cyber adversaries.

YARA Rule

rule Dubnium_Sample_2
{

    meta:
        description = "Detects sample mentioned in the Dubnium Report"
        author = "Florian Roth"
        reference = "https://goo.gl/AW9Cuu"
        date = "2016-06-10"
        hash1 = "5246899b8c74a681e385cbc1dd556f9c73cf55f2a0074c389b3bf823bfc6ce4b"

    strings:
        $x1 = ":*:::D:\\:c:~:" fullword ascii
        $s2 = "SPMUVR" fullword ascii

    condition:
        ( uint16(0) == 0x5a4d and filesize < 2000KB and all of them )
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

• Microsoft Defender for Endpoint — Custom indicators / advanced hunting
• Email Gateway — Attachment scanning
• File Share Monitoring — Periodic scanning of shared drives
• YARA CLI — Manual threat hunting on endpoints

This rule contains 2 string patterns in its detection logic.

References

• https://goo.gl/AW9Cuu
• Source Rule

False Positive Guidance

• Scenario: A system administrator is using PowerShell to run a scheduled job that performs routine system diagnostics, which includes checking for known malware signatures.
  Filter/Exclusion: Exclude processes associated with powershell.exe when the command line includes -Command and contains Get-Content or Invoke-Command with known diagnostic scripts.

• Scenario: A Windows Task Scheduler job is configured to run a script that validates system integrity using Sysmon logs, which may include hashes of known benign files.
  Filter/Exclusion: Exclude events where the process name is schtasks.exe and the command line includes -Execute with a script path containing Sysmon or IntegrityCheck.

• Scenario: A Windows Admin Center session is being used to remotely manage a server, and the session includes the use of PowerShell to run administrative tasks such as updating software or configuring settings.
  Filter/Exclusion: Exclude processes initiated from Windows Admin Center by checking the LogonSession or RemoteAddress fields, or by filtering out processes with msiexec.exe or wmic.exe.

• Scenario: A scheduled backup job using Veeam Backup & Replication is running, which may include scanning or processing files that match the hash or name of a sample listed in the Dubnium Report.
  Filter/Exclusion: Exclude processes where the parent process is veeam.exe or where the command line includes backup or snapshot related keywords.

• Scenario: A Windows Update or Microsoft Endpoint Manager (MEM) task is running, which may temporarily include files or hashes that match those in the Dubnium Report during patching or configuration.
  Filter/Exclusion: Exclude events where the process name is wuauclt.exe, `setup.exe