URLhaus: d52f85 Malicious URLs

Hunt Hypothesis

This hunt detects adversary behavior involving the consumption of newly identified malicious web resources flagged by URLhaus, specifically targeting threats associated with the d52f85 signature to identify potential command and control or phishing activities. The SOC team should proactively hunt for these indicators within Azure Sentinel to rapidly isolate compromised endpoints before they can establish persistence or exfiltrate sensitive data through unmonitored network channels.

IOC Summary

Threat: d52f85 Total URLs: 2 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

Here are 4 specific false positive scenarios for the URLhaus: d52f85 Malicious URLs rule, including suggested filters and exclusions tailored for an enterprise environment:

• Scenario: Automated Security Scanner Probing

  • Context: Internal vulnerability scanners (e.g., Tenable Nessus, Qualys, or Rapid7 InsightVM) frequently crawl external endpoints to verify certificate validity or check for known threats. These tools often generate HTTP requests to URLs that URLhaus has flagged as “suspicious” but which are safe in the context of a controlled scan.
  • Filter/Exclusion: Exclude traffic originating from specific scanner IP ranges (e.g., Source_IP IN [10.20.30.0/24]) or filter by User-Agent strings containing keywords like “Tenable,” “Qualys,” or “Rapid7.”

• Scenario: Scheduled Cloud Backup and Sync Operations

  • Context: Enterprise backup solutions (e.g., Veeam, Rubrik, or Microsoft Azure Backup) perform scheduled synchronization jobs that connect to cloud storage endpoints. If a specific storage endpoint URL has been recently tagged by URLhaus due to a transient issue elsewhere, the regular backup heartbeat will trigger this rule unnecessarily.
  • Filter/Exclusion: Create an exclusion for the service account used by the backup agent (e.g., User_Principal_Name = 'svc-backup-agent') or whitelist specific destination domains known to be part of the backup infrastructure (e.g., *.azure.com, *.veeam.com).

• Scenario: Software Update Mechanisms

  • Context: Critical enterprise applications such as Microsoft Office 365, Adobe Creative Cloud, or Java Runtime Environment execute scheduled update checks. These mechanisms often query dynamic URLs that may be newly registered