URLhaus: Mozi Malicious URLs

Hunt Hypothesis

This hunt detects adversary activity involving the Mozi malware family by identifying traffic to six specific malicious URLs known to deliver this threat. A SOC team should proactively search for these indicators in Azure Sentinel to rapidly isolate compromised endpoints and prevent lateral movement before the malware establishes persistence or exfiltrates sensitive data.

IOC Summary

Threat: Mozi Total URLs: 6 Active URLs: 6

KQL: Url Dns Hunt

// Hunt for DNS resolution of URLhaus malicious domains
// Threat: Mozi
let malicious_domains = dynamic(["125.40.73.55", "221.15.191.128", "123.8.8.31", "42.232.87.174", "125.44.53.29"]);
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(["125.40.73.55", "221.15.191.128", "123.8.8.31", "42.232.87.174", "125.44.53.29"]);
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: Mozi Malicious URLs detection rule, including suggested filters and exclusions tailored for an enterprise environment:

• Scenario: Automated Vulnerability Scanning by Security Tools

  • Context: Enterprise vulnerability scanners (e.g., Tenable Nessus, Qualys, or Rapid7 InsightVM) frequently probe external endpoints to verify patch levels. These tools often generate high volumes of HTTP/HTTPS requests that may match the Mozi signature pattern due to specific User-Agent strings or URL structures used during discovery phases.
  • Filter/Exclusion: Create a rule exclusion based on the source IP ranges of your scanning appliances (e.g., 10.50.20.0/24) and filter out traffic where the User-Agent contains “Tenable,” “Qualys,” or “Rapid7.”

• Scenario: Scheduled Backup and Cloud Sync Operations

  • Context: Automated backup agents (e.g., Veeam, Rubrik, or Microsoft Azure Backup) and file synchronization services (e.g., OneDrive for Business, Box Enterprise) regularly connect to external storage gateways. These connections often utilize complex URL parameters that can trigger the Mozi detection logic, particularly when accessing specific CDN endpoints used by these vendors.
  • Filter/Exclusion: Exclude traffic originating from known backup service accounts (e.g., svc-backup-01) or filter URLs containing vendor-specific domains such as .veeam.com, .azureedge.net, and .box.com if they are not flagged as malicious by the URLhaus feed.

• Scenario: Third-Party API Integration for HR and Finance

  • Context: Internal applications integrate with external SaaS platforms like Workday, SAP SuccessFactors, or Oracle NetSuite.