URLhaus: malware_download Malicious URLs

Hunt Hypothesis

The hypothesis is that the detected malicious URLs are used by adversaries to download malware into the network, bypassing traditional defenses. SOC teams should proactively hunt for these URLs in Azure Sentinel to identify and mitigate potential malware infections before they spread.

IOC Summary

Threat: malware_download Total URLs: 2 Active URLs: 2

KQL: Url Dns Hunt

// Hunt for DNS resolution of URLhaus malicious domains
// Threat: malware_download
let malicious_domains = dynamic(["42.232.238.243"]);
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(["42.232.238.243"]);
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: A system administrator is downloading a known malicious URL as part of a security tool update.
  Filter/Exclusion: Exclude URLs that match known security tool update domains (e.g., update.microsoft.com, download.qualys.com).

• Scenario: A scheduled job is fetching malware samples from a sandboxing platform for analysis.
  Filter/Exclusion: Exclude URLs that match sandboxing platforms (e.g., sandboxed.sinful.io, malwareanalysis.com).

• Scenario: A user is accessing a legitimate phishing detection tool that uses a known malicious URL for testing purposes.
  Filter/Exclusion: Exclude URLs associated with phishing detection and testing tools (e.g., phishing-test-url.com, test-phishing-link.net).

• Scenario: A DevOps pipeline is using a CI/CD tool that temporarily hosts malware analysis artifacts.
  Filter/Exclusion: Exclude URLs that match CI/CD artifact storage locations (e.g., artifactory.example.com, ci.example.org).

• Scenario: An internal tool is used to distribute malware analysis reports, and the URL is flagged as malicious.
  Filter/Exclusion: Exclude URLs that match internal reporting tools (e.g., internal.analysis.reports.example.com, reporting.tools.example.org).