URLhaus: exe Malicious URLs

Hunt Hypothesis

This hypothesis detects adversary behavior where endpoints attempt to download or execute executable files from URLs identified by URLhaus as hosting known malware signatures. A SOC team should proactively hunt for this activity in Azure Sentinel to rapidly identify and isolate potential initial access vectors before malicious executables compromise the internal network.

IOC Summary

Threat: exe Total URLs: 4 Active URLs: 2

KQL: Url Dns Hunt

// Hunt for DNS resolution of URLhaus malicious domains
// Threat: exe
let malicious_domains = dynamic(["176.65.139.201", "manbipll.duckdns.org"]);
DnsEvents
| where Name has_any (malicious_domains)
| project TimeGenerated, Computer, Name, IPAddresses
| order by TimeGenerated desc

KQL: Url Proxy Hunt

// Hunt for web traffic to URLhaus malicious domains
let malicious_domains = dynamic(["176.65.139.201", "manbipll.duckdns.org"]);
CommonSecurityLog
| where RequestURL has_any (malicious_domains) or DestinationHostName has_any (malicious_domains)
| project TimeGenerated, SourceIP, RequestURL, DestinationHostName, DeviceAction
| order by TimeGenerated desc

Required Data Sources

References

• URLhaus

False Positive Guidance

Here are 5 specific false positive scenarios for the URLhaus: exe Malicious URLs detection rule, including tailored filters and exclusions suitable for an enterprise environment:

• Scenario: Automated Software Deployment via Endpoint Management Tools

  • Context: Enterprise tools like Microsoft Intune, Jamf, or SCCM (Configuration Manager) frequently pull .exe installers from public repositories (e.g., GitHub Releases, Chocolatey) to deploy updates. These URLs often contain executable payloads that URLhaus flags as “suspicious” due to the generic nature of auto-generated download links.
  • Filter/Exclusion: Create a whitelist for known deployment servers and specific hash ranges. Exclude traffic originating from internal IP ranges (e.g., 10.x.x.x) or specific hostnames like *.intune.microsoft.com and chocolatey.org where the destination URL contains .exe.

• Scenario: Scheduled Antivirus Definition Updates

  • Context: Security suites such as CrowdStrike Falcon, SentinelOne, or Microsoft Defender for Endpoint run scheduled jobs (e.g., every 4 hours) to download signature definition files. These updates are often distributed via .exe wrappers from the vendor’s update servers, which can trigger false positives if the URL structure changes slightly between releases.
  • Filter/Exclusion: Implement a time-based exclusion for known maintenance windows (e.g., 02:00 - 04:00 UTC) or exclude specific vendor domains such as *.crowdstrike.com, *.sentinelone.net, and go.microsoft.com when the User-Agent string contains “DefenderUpdate” or “FalconSensor”.

• Scenario: Legitimate Cloud Storage Sync Operations

  • Context: Users utilizing Microsoft OneDrive, Google Drive for Desktop, or **