Analyzing Malicious URL with URLScan

Overview

URLScan.io is a free service for scanning and analyzing suspicious URLs. It captures screenshots, DOM content, HTTP transactions, JavaScript behavior, and network connections of web pages in an isolated environment. This skill covers using URLScan's web interface and API to investigate phishing URLs, credential harvesting pages, and malicious redirects without exposing the analyst's system to risk.

When to Use

• When investigating security incidents that require analyzing malicious url with urlscan
• When building detection rules or threat hunting queries for this domain
• When SOC analysts need structured procedures for this analysis type
• When validating security monitoring coverage for related attack techniques

Prerequisites

• URLScan.io account (free tier available, API key for automation)
• Python 3.8+ with requests library
• Understanding of HTTP protocols and web technologies
• Familiarity with phishing URL patterns

Key Concepts

URLScan Capabilities

1. Safe browsing: Renders URLs in isolated Chromium instance
2. Screenshot capture: Visual snapshot of the rendered page
3. DOM analysis: Full HTML content after JavaScript execution
4. Network log: All HTTP requests made by the page (HAR format)
5. Certificate analysis: SSL/TLS certificate details
6. Technology detection: Identifies web frameworks and libraries
7. IP/ASN mapping: Infrastructure intelligence
8. Verdict: Community and automated classification

Phishing URL Red Flags

• Newly registered domains (< 30 days)
• Free hosting services (Wix, GitHub Pages, Firebase)
• URL shorteners hiding final destination
• Excessive subdomain depth (login.microsoft.com.evil.com)
• Brand name in subdomain or path, not domain
• Non-standard ports
• Data URIs or base64-encoded content
• JavaScript-heavy pages with minimal HTML

Workflow