URLhaus: ua-wget Malicious URLs

Hunt Hypothesis

This detection identifies adversary activity involving the execution of wget tools to download payloads from five specific malicious URLs known in the URLhaus threat intelligence feed. A SOC team should proactively hunt for this behavior in Azure Sentinel to rapidly isolate compromised endpoints and prevent lateral movement or data exfiltration driven by these high-severity web-based threats.

IOC Summary

Threat: ua-wget Total URLs: 5 Active URLs: 0

KQL: Url Dns Hunt

// Hunt for DNS resolution of URLhaus malicious domains
// Threat: ua-wget
let malicious_domains = dynamic(["129.121.110.105"]);
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(["129.121.110.105"]);
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: ua-wget Malicious URLs detection rule, including suggested filters and exclusions tailored for an enterprise environment:

• Automated Software Patching via Wget Scripts

  • Scenario: System administrators or automated patch management tools (e.g., Ansible, Chef, or custom Bash/PowerShell scripts) utilize the wget command to download security patches, configuration files, or software installers from trusted vendor repositories. These downloads often trigger the rule because the User-Agent string explicitly contains “Wget,” and the destination URLs may be newly published by vendors, causing URLhaus to flag them as suspicious before full reputation is established.
  • Filter/Exclusion: Create an exclusion for traffic originating from known Patch Management Servers (e.g., WSUS servers, SCCM sites) or specific service accounts running automation scripts. Additionally, filter out URLs belonging to trusted vendor domains (e.g., *.microsoft.com, *.oracle.com) where the User-Agent is “Wget” and the HTTP status code is 200 OK.

• CI/CD Pipeline Artifact Retrieval

  • Scenario: In DevOps environments, Continuous Integration/Continuous Deployment (CI/CD) platforms like Jenkins, GitLab CI, or Azure DevOps frequently use wget within build agents to fetch dependencies, Docker images, or release artifacts from internal artifact repositories (e.g., Nexus, Artifactory) or external package managers. The build agents often run as headless services with the “Wget” user agent, generating high-volume traffic that mimics malicious scanning behavior.
  • Filter/Exclusion: Exclude network segments dedicated to Build Agents and CI/CD Controllers. Implement a rule exception for URLs matching internal artifact repository domains (e.g., `