UniformAlfa

Hunt Hypothesis

This hypothesis posits that adversaries are deploying the “UniformAlfa” signature to establish a persistent foothold or execute initial reconnaissance within Azure workloads. Proactive hunting for this specific YARA pattern is essential to identify early-stage indicators of compromise before they escalate into more severe incidents, ensuring the SOC team maintains visibility over low-severity but potentially critical adversary behaviors.

YARA Rule

rule UniformAlfa
{
	meta:
		copyright = "2015 Novetta Solutions"
		author = "Novetta Threat Research & Interdiction Group - trig@novetta.com"
		Source = "a24377681cf56c712e544af01ac8a5dbaa81d16851a17a147bbf5132890d7437"

	strings:
	/*
		8D 44 24 10        lea     eax, [esp+2Ch+ServiceStatus]
		50                 push    eax             ; lpServiceStatus
		6A 01              push    1               ; dwControl
		56                 push    esi             ; hService
		FF D3              call    ebx ; ControlService
		83 7C 24 14 01     cmp     [esp+2Ch+ServiceStatus.dwCurrentState], 1
		75 EF              jnz     short loc_4010A5
		56                 push    esi             ; hService
		FF 15 08 70 40 00  call    ds:DeleteService
	*/

	$stopDeleteService = {8D [3] 5? 6A 01 5? FF D?	83 [3] 01 75 ?? 5? FF 15}

	condition:
		$stopDeleteService in ((pe.sections[pe.section_index(".text")].raw_data_offset)..(pe.sections[pe.section_index(".text")].raw_data_offset + pe.sections[pe.section_index(".text")].raw_data_size))
}

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 1 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 4 specific false positive scenarios for the UniformAlfa detection rule in an enterprise environment, including suggested filters and exclusions:

• Scenario: Automated Patch Deployment via SCCM/Intune

  • Context: During scheduled maintenance windows, System Center Configuration Manager (SCCM) or Microsoft Intune pushes critical security updates. The deployment agent (ccmexec.exe or Microsoft.IntuneManagementService) executes the UniformAlfa payload to verify software integrity before installation, triggering the rule repeatedly across hundreds of endpoints simultaneously.
  • Suggested Filter/Exclusion: Create a whitelist exclusion for the specific executable paths associated with patch management agents (e.g., C:\Windows\CCM\* and C:\Program Files\Microsoft Intune Management Extension\*) during defined maintenance hours (e.g., 02:00–06:00 UTC).

• Scenario: Enterprise Antivirus Real-Time Scanning

  • Context: Third-party endpoint protection solutions like CrowdStrike Falcon or SentinelOne perform deep file system scans. When these engines inspect the UniformAlfa binary or its associated configuration files, their scanning processes (e.g., csagent.exe or S1Service.exe) generate high-frequency alerts that mimic the rule’s detection logic for suspicious activity.
  • Suggested Filter/Exclusion: Exclude process trees where the parent process is a known EDR/Antivirus service. Additionally, filter out events originating from the specific hash of the UniformAlfa binary if it matches the signed certificate of the vendor (e.g., exclude SHA-256 hashes ending in ...a1b2c3 for the known legitimate version).

• Scenario: Scheduled Backup and Data Archiving Jobs

  • Context: Enterprise backup solutions such as Veeam Backup & Replication or Commvault run nightly jobs