The Redirect Chain That Bypasses Your Ad Blocker

Description and use

A redirect‑chain analyzer detects malicious ad clicks by measuring hop count, timing, and header changes, bypassing static blocklists.

Problem

Static ad‑blocker blocklists miss malicious ads that use fast‑rotating multi‑hop redirect chains, allowing attackers to bypass filters before domains appear on blocklists.

Outcome

The analyzer detects malicious redirect chains by focusing on behavioral signals rather than domain names, enabling real‑time blocking of novel malicious ads.

Workflow

• 1. Install Python and requests library.
• 2. Copy the provided analyze_redirect_chain function into a script.
• 3. Optionally create a YAML config to set max_hops, whitelist_domains, score_threshold, and ignore_known_platforms.
• 4. Run the script against target URLs to collect hop metadata.
• 5. Feed the hop data into a scoring algorithm that weights hop count, delay variance, and header anomalies.
• 6. Flag chains exceeding the score_threshold for manual review or automated blocking.
• 7. Update the whitelist and thresholds as needed to reduce false positives.

Evidence

Static blocklists fail because they only check the final destination. An attacker can create a new domain, run it briefly, and move on before your list refreshes.

Source

The function captures the status code, next location, elapsed time, and the referrer policy at each step.

Source

A score based solely on hop count will flag real campaigns. Adding a whitelist of known ad-platform domains reduces noise while maintaining sensitivity.

Source