Suspicious AiTM Session Cookie Exfiltration to log_cookie Endpoint

ATT&CK techniques

Initial Access → Cred Access

Recon
Resource Dev
Initial Access
- T1078.004Cloud Accounts
Execution
Persistence
- T1078.004Cloud Accounts
Priv Esc
- T1078.004Cloud Accounts
Defense Evasion
- T1078.004Cloud Accounts
Cred Access
- T1539Steal Web Session Cookie
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects web requests to a log_cookie collection endpoint carrying stolen session identifiers such as idx, JSESSIONID, and sid, the harvesting path used by the AiTM phishing kit. The reverse proxy captures live authenticated cookies from M365 and Okta victims and ships them to attacker infrastructure for session hijacking. Traffic to this endpoint with session token parameters indicates successful token theft.

Reporting behind it

Related detections9 linkedT1539 — drag to rearrange

Suspicious Entra Sign-In to OfficeHome with axios User Agent

Suspicious 1Phish Kit Cookies and Telemetry Beacon

Possible SES Sending Configuration Enumeration via CloudTrail

Suspicious AWS Role Assumption via Cognito Web Identity

Malicious Madgicx Plus Extension C2 Domain Resolution

Suspicious Google Cloud Function Create or Update Triggering Build

Malicious RemusStealer Credential Exfiltration to pics TLD C2

Possible Citrix Bleed Session Token Leak via OpenID Configuration Endpoint (CVE-2023-4966) (via webserver)

Uncommon Browser Launched with Remote Debugging Port for Cookie Theft (via process_creation)

Suspicious AiTM Session Cookie Exfiltration to log_cookie Endpoint

Pivot detection · T1539 · 9 related

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

Full detection rule

Unlock this rule to view and copy it

The detection logic is included with a plan. Everything else — context, mappings and implementation details — stays free on this page.

Sign in for 3 free unlocks

Signing in gives you 3 unlocks to spend on any rule in the library. No card, and they do not expire.

Also included

Unlocked rules convert on this page — to Splunk SPL or Splunk — Raw Index SPL or Microsoft Sentinel KQL or Microsoft Sentinel ASIM ASIM KQL or Microsoft Defender XDR KQL or Elastic Security KQL or Elastic Security Lucene or Elastic Security ES|QL or CrowdStrike Falcon CQL or SentinelOne PowerQuery or Palo Alto Cortex XDR XQL or Carbon Black Cloud Platform Search or Carbon Black EDR Process Search or Google Security Operations UDM Search or IBM QRadar AQL or Sumo Logic Cloud SIEM Rules expression or Rapid7 InsightIDR LEQL or Graylog Search or OpenSearch Lucene or OpenSearch PPL PPL or Grafana Loki LogQL or SQLite SQL or Zircolite SQLite — with the log-source profile the engine picked, the field map it used, and everything it could not express. Converting a rule you have unlocked costs no further credit.

See it run on a free rule →Convert your own rule →