URL Risk Analysis

Zulu URL Risk Analyzer (zulu.zscaler.com) is a free URL analysis and risk scoring service operated by Zscaler, a leading cloud security company. For security analysts, threat intelligence researchers, and OSINT investigators evaluating the safety and reputation of URLs, Zulu provides automated risk assessment backed by Zscaler's extensive threat intelligence infrastructure.

Zulu analyzes submitted URLs across multiple dimensions: the hosting domain's reputation history, content category (what type of site it is), security policy violations detected in page content, associated IP address reputation, SSL certificate validity, and whether the URL or domain appears in Zscaler's threat intelligence feeds. The result is a risk score from 0 to 100 with detailed breakdowns by risk factor.

The content categorization is particularly useful for OSINT: Zulu classifies pages into categories (news, social media, adult content, gambling, phishing, malware, command-and-control, etc.), providing immediate context about a URL's purpose even before examining the page directly. A URL categorized as "command-and-control" or "phishing" by Zscaler's systems has almost certainly been confirmed malicious by prior investigation.

For incident responders triaging suspicious URLs from phishing reports or SIEM alerts, Zulu provides a rapid first-pass assessment. A high risk score indicates immediate follow-up is warranted, while a low score with a legitimate category may deprioritize the URL in a queue of events awaiting analysis.

Zscaler's threat intelligence reflects real-world telemetry from millions of enterprise users passing traffic through Zscaler's cloud proxy — giving the risk scoring substantial data backing compared to smaller intelligence providers. This breadth of telemetry makes Zulu particularly reliable for identifying known bad infrastructure.

Limitations include time lag for new threats — domains registered recently for a specific phishing campaign may not yet have accumulated sufficient reputation data for accurate scoring. Always supplement Zulu analysis with URLScan.io, VirusTotal, and manual page inspection for complete assessment.

Document the analyzed URL, risk score, category classification, and scan date in security incident records.