URLhaus: botnetdomain Malicious URLs

Hunt Hypothesis

This hunt targets adversary behavior where compromised endpoints communicate with known botnet command-and-control domains to establish persistent remote access and data exfiltration channels. Proactively hunting for these specific URLhaus-tagged malicious URLs in Azure Sentinel is critical to identify early-stage infections before they expand into a coordinated network-wide botnet attack.

IOC Summary

Threat: botnetdomain Total URLs: 15 Active URLs: 0

KQL: Url Dns Hunt

// Hunt for DNS resolution of URLhaus malicious domains
// Threat: botnetdomain
let malicious_domains = dynamic(["codeinspector.ddns.net"]);
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(["codeinspector.ddns.net"]);
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 specific false positive scenarios for the URLhaus: botnetdomain Malicious URLs detection rule, tailored for an enterprise environment:

• Antivirus Definition Updates via Central Management Console

  • Scenario: Enterprise endpoint protection suites (e.g., CrowdStrike Falcon, SentinelOne, or Microsoft Defender for Endpoint) frequently pull definition updates from shared vendor repositories. These update servers often host thousands of subdomains that may be flagged by URLhaus as “botnetdomain” due to high traffic volume and dynamic IP rotation, even though they are legitimate sources for security patches.
  • Filter/Exclusion: Create an exclusion rule for the specific process names associated with the AV agent (e.g., CmService.exe, SentinelOneAgent.exe) accessing known vendor update domains (e.g., *.crowdstrike.com, *.sentinelone.net).

• Scheduled Software Patching and Deployment Jobs

  • Scenario: Automated deployment tools like Microsoft SCCM, Ivanti Endpoint Manager, or Ansible Tower execute scheduled jobs to download software binaries and configuration scripts. These tools often connect to public content delivery networks (CDNs) or third-party software repositories (e.g., chocolatey.org, github.com) where specific subdomains used for asset distribution may be misidentified as botnet infrastructure by the URLhaus feed.
  • Filter/Exclusion: Whitelist traffic originating from the deployment server’s IP range or specific service accounts (e.g., svc-ccm-agent) connecting to known software repository domains, excluding them from the “botnetdomain” tag alert logic.

• Legacy Application Connectivity and API Integrations

  • Scenario: Older line-of-business applications (e.g., legacy ERP modules or custom .NET web apps) often rely on external APIs for data synchronization. These applications