LY WGKXwwwszleyucom

Hunt Hypothesis

This detection identifies potential malicious activity associated with the specific indicator “LY WGKXwwwszleyucom,” which may represent a novel or evolving threat signature within the network environment. Proactively hunting for this pattern in Azure Sentinel is essential to validate its legitimacy and prevent low-severity signals from escalating into undetected lateral movement or data exfiltration incidents.

YARA Rule

rule LY_WGKXwwwszleyucom
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 4D 79 46 75 6E 00 62 73 }

condition:
		$a0
}

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 LY WGKXwwwszleyucom detection rule in an enterprise environment, along with recommended filters and exclusions:

• Scenario: Microsoft Defender Antivirus Cloud Protection Updates

  • Context: The YARA rule likely flags network traffic or file artifacts associated with www.szleyu.com (or similar domains) which are part of the Microsoft Defender for Endpoint cloud protection update mechanism. When the endpoint agent pulls definition updates, it may generate a signature that matches the rule’s logic.
  • Filter/Exclusion: Create an exclusion in the SIEM query to ignore events where the Process Name is MsMpEng.exe or SenseService.exe and the Destination Domain contains microsoft.com. Alternatively, add the specific hash of the update payload to a “Known Good” allowlist.

• Scenario: Scheduled PowerShell Job for Azure AD Sync

  • Context: An enterprise often runs scheduled tasks (e.g., via Task Scheduler) that execute PowerShell scripts to synchronize identities or fetch configuration data from external cloud services. If these scripts invoke Invoke-WebRequest against a partner domain matching the rule’s pattern, it triggers a hit.
  • Filter/Exclusion: Exclude events where the Parent Process Name is TaskHost.exe and the Command Line contains specific keywords like “AzureADSync” or “GraphAPI”. A filter condition could be: ProcessName = 'powershell.exe' AND CommandLine LIKE '%sync%'.

• Scenario: Web Application Firewall (WAF) Health Checks

  • Context: Internal load balancers (such as F5 Big-IP or AWS ALB) perform continuous HTTP GET requests to verify the health of backend web servers. If these health checks route through a proxy that resolves to the domain pattern in the rule,