URLhaus: d52f85 Malicious URLs

Hunt Hypothesis

This hunt detects adversary activity involving network traffic to specific malicious URLs identified by URLhaus with the tag d52f85, which often indicate active phishing campaigns or command-and-control communications for compromised endpoints. Proactively hunting for these indicators in Azure Sentinel is critical because early identification of these high-severity threats allows the SOC team to isolate affected assets and block malicious traffic before lateral movement or data exfiltration occurs.

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(["inventorychanger.com", "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(["inventorychanger.com", "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 detection rule, along with targeted filters and exclusions:

• Scenario: Automated Security Scanner Traffic

  • Context: Internal vulnerability scanners (e.g., Tenable Nessus, Qualys, or Rapid7 InsightVM) frequently probe external endpoints to verify certificate validity or service availability. These tools often generate high-volume HTTP/HTTPS requests to known public URLs that the URLhaus feed may have recently flagged as “d52f85” due to transient reputation issues, even though the scanner’s traffic is benign.
  • Filter/Exclusion: Create a rule exclusion based on the source IP range of the security scanning appliances (e.g., Source_IP IN 10.20.30.0/24) or filter out events where the user agent string contains specific keywords like “Nessus”, “Qualys”, or “Rapid7”.

• Scenario: Scheduled Cloud Backup & Sync Jobs

  • Context: Enterprise data backup solutions (e.g., Veeam, Rubrik, or Microsoft Azure Backup) and file synchronization tools (e.g., OneDrive for Business, Box Enterprise) execute scheduled jobs that connect to external cloud storage endpoints. If a specific storage endpoint URL has been recently updated in the URLhaus feed with the d52f85 tag, these routine backup heartbeats will trigger alerts despite being legitimate administrative traffic.
  • Filter/Exclusion: Exclude events occurring during defined maintenance windows (e.g., 01:00–04:00 UTC) where the destination URL matches known cloud storage domains (e.g., *.blob.core.windows.net, *.box.com) and the process name is identified as a backup service executable.