URLhaus: d52f85 Malicious URLs

Hunt Hypothesis

This hypothesis targets potential web-based intrusion attempts by identifying user interactions with three known malicious URLs associated with the d52f85 tag, which often serve as initial access vectors for phishing or drive-by download attacks. Proactively hunting for these specific indicators in Azure Sentinel allows the SOC to detect compromised endpoints or active sessions before lateral movement occurs, leveraging high-severity intelligence to reduce mean time to detection.

IOC Summary

Threat: d52f85 Total URLs: 3 Active URLs: 0

KQL: Url Dns Hunt

// Hunt for DNS resolution of URLhaus malicious domains
// Threat: d52f85
let malicious_domains = dynamic(["62.60.226.140"]);
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(["62.60.226.140"]);
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

• Scenario: Automated Web Scraping or Monitoring Tools

  • Context: Tools like Burp Suite, OWASP ZAP, or custom Python scripts using requests/httpx may probe known malicious endpoints (including d52f85-tagged URLs) to verify content changes, check for new payloads, or validate that a block rule is active.
  • Filter/Exclusion: Exclude traffic originating from service accounts or specific hostnames (e.g., *scanner*, *monitoring*) and filter for user agents containing python-requests, curl, or ZAP.

• Scenario: Developer Localhost Testing or Staging Environments

  • Context: Developers testing API integrations or frontend components in local environments (e.g., Docker Compose, Kubernetes staging clusters) may use the malicious URLs as placeholder endpoints or test fixtures to simulate external dependencies before deploying to production.
  • Filter/Exclusion: Exclude traffic where the destination IP is within the internal RFC1918 range (10.x.x.x, 172.16.x.x–172.31.x.x, 192.168.x.x) or where the source host is tagged with env:staging or env:dev.

• Scenario: Scheduled Cron Jobs for Cache Warmup or Health Checks

  • Context: Scheduled jobs (e.g., Cron, Systemd Timers, or Windows Task Scheduler) that perform cache warming, CDN pre-fetching, or health checks may inadvertently hit these URLs if they are part of a broader list of external dependencies or if a configuration file was not updated after a URL rotation.
  • Filter/Exclusion: Exclude events where the process name is cron, `system