Suspicious Tycoon 2FA Credential Exfiltration Fields

PremiumReviewedSigma · Medium · v1
Category
proxy
Author
HuntRule
Published
2026-06-28
Updated
2026-08-28

ATT&CK techniques

Cred Access → Collection
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Discovery

  9. Lateral Movement

  10. C2

  11. Exfiltration

  12. Impact

What it detects

This rule detects HTTP requests carrying the Tycoon 2FA exfiltration parameters bltdip, bltdref, bltdua and bltddata. These custom field names package the stolen victim context and session data sent back to the phishing kit, uniquely marking AiTM credential theft.

Related detections9 linkedT1557 — drag to rearrange
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Malicious TCP Session Hijacking via rshijack
Suspicious Entra ID Auth Broker Sign-In With Node.js User Agent via Tycoon 2FA
Malicious EdgeStepper iptables DNS Redirection for Adversary-in-the-Middle
Suspicious Entra Sign-In to OfficeHome with axios User Agent
Suspicious Entra Sign-In Interrupt With High Aggregated Risk via AiTM DNS Hijacking (via azure)
Possible Adversary-in-the-Middle Proxy Login via Crafted URL Parameters
Possible Mamba 2FA AiTM Phishing URL Pattern
Malicious Tycoon 2FA AiTM Phishing WebSocket Channel
Suspicious Tycoon 2FA Credential Exfiltration Fields
Pivot detection · T1557 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.