Enterprise platforms love to “protect” you. So much so that they’ll hijack your links, bury the destination in a multi-redirect chain, and call it a security feature. But for SOC teams, DFIR analysts, and blue teamers who depend on clean attribution and fast incident response, these redirection behaviors are not protection — they’re obstruction.

📌 TTP Context

Redirection behaviors are common in modern enterprise email ecosystems. Under the guise of:

• 🔎 Tracking click-through metrics
• 🛡️ Pre-click threat analysis
• 📈 Behavioral analytics

…these platforms wrap every outbound link in redirector chains that obscure the real destination.

They commonly appear like this:

https://redirect.corpdomain.com/url?q=https%3A%2F%2Flegit-site.com%2Fauth%2Freset&source=email&usg=randomstring

In practice, this:

• 🧩 Breaks SAML/MFA and token workflows (especially when time-sensitive)
• 🔒 Obscures IOC visibility for SOC analysts
• 🧼 Interferes with safe sandboxing and URL decoding in phishing investigations

💣 Preemptive Strike: “But You Shouldn’t Click Links”

Sure. In a vacuum, don’t click suspicious links. But in actual enterprise environments, links are **required to function.**

• 🔐 Approve new devices? Click the link.
• 🔄 Reset your password? Click the link.
• 📄 Open your job offer or onboarding portal? Click the link.
• 🔍 Investigate phishing click behavior? You’ll be clicking links. Carefully.

SOC and DFIR teams aren’t just passive observers — they investigate, pivot, decode, and trace.

🔬 Exploitation Detail

Redirector patterns often encode the destination into a query string:

https://example.com/redirect?u=https%3A%2F%2Ftargetsite.com

Some even double-encode the URL or add anti-bot parameters that make extraction harder:

https://secure.platform.com/track?u=aHR0cHM6Ly90YXJnZXRzaXRlLmNvbS9hdXRoL3Jlc2V0

These can silently expire, break after forwardings, or fail if the redirection platform filters the query mid-hop.

📎 Attacker Behavior Snapshot

Threat actors use redirection chains to:

• 🕵️ Obfuscate phishing destinations
• 💣 Evade simple IOC matching in email security tools
• 🔀 Chain multiple redirectors (open redirect + tracking + payload)

Example chain:

https://mail-corp.com/track?q=https://redirect.biz/fwd?q=https://malicious.site/login.php

Each hop hides the final payload behind telemetry or redirect logic.

🧪 YARA Rule (HTML redirector pattern)

rule Redirector_URL_Pattern
{
  strings:
    $url1 = "https://redirect"
    $url2 = "?q=https"
    $url3 = "%3A%2F%2F"
  condition:
    all of them
}

🌐 Suricata Rule (HTTP Redirect Chain)

alert http any any -> any any (
  msg:"HTTP Redirector Detected - Potential Obfuscation";
  flow:to_server,established;
  content:"/url?q="; http_uri;
  content:"https"; http_uri;
  classtype:bad-unknown;
  sid:2025080801;
  rev:1;
)

⚡ Sigma Rule (App/Proxy Logs)

title: Redirector Link in Web Proxy Logs
logsource:
  category: proxy
detection:
  selection:
    url|contains:
      - "/url?q=https"
      - "/redirect?u="
  condition: selection
level: medium

📊 Splunk Query (Enterprise Redirect Hunt)

index=proxy_logs OR index=webgateway
| eval decoded_url=urldecode(uri)
| search decoded_url="https://*" AND uri="*/url?q=*"
| stats count by src_ip, decoded_url, uri

🛠️ SOC Detection Strategy

• 👀 Tier 1: Flag repeated redirect hits from unusual source IPs or service accounts
• 🔍 Tier 2: Decode and extract true destinations for analysis or sandboxing
• 📌 Tier 3: Build redirection maps to trace multi-hop chains and detect anomaly usage

Focus log coverage on:

• 🌐 Web proxy and firewall logs
• 📧 Email gateway logs
• 🧠 Endpoint telemetry for URL string access or browser injection

🔐 Hardening & Mitigation

• 🛑 Avoid platforms that strip or mangle email links via redirection logic
• 🧩 Build browser plugins to automatically decode or warn about redirector chains
• 🔐 Require redirect domains to be logged as part of your SIEM pipeline
• 🔧 Customize email templates in your enterprise stack to avoid broken tracking logic

📋 Incident Response Snippets

• 🛠️ grep/regex the true link from redirector patterns in email headers or body
• 🔎 Identify users who clicked redirection URLs leading to MFA, reset, or onboarding failures
• 🚫 Invalidate exposed tokens or sessions if redirector leaks destination parameters
• 🧹 Review logs for failed authentications correlated to broken links

📚 Suggested Reading

• Vendor Docs: Customize redirect behavior
• RFC 7231: HTTP 3xx Redirects
• MITRE ATT&CK T1204.002 — Malicious Links

🧾 Final Thoughts

Link redirection isn’t just a convenience or a nuisance — it’s a visibility blocker and a forensic risk. When the true destination is hidden or expired, and the security platform calls it protection, we have a problem.

Because when tokens fail, MFA links break, and phishing flows can’t be sandboxed — defenders are left blindfolded.

The solution? Build workflows that respect analyst visibility, prioritize transparency, and stop calling telemetry siphoning a “feature.”

When clicks become clues — don’t hide the clues.

Published: August 8, 2025