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Description

This analytic identifies instances where multiple client attributes (such as IP, User Agent, etc.) associated with the same Device Token change for a specific user. It aims to detect scenarios where an adversary might attempt to reuse a stolen web session cookie. \

  • It retrieves policy evaluation events from successful authentication attempts. \
  • It aggregates and groups these events by Device Token and User, providing the first policy evaluation event within the search window. \

  • It checks for the presence of more than one IP and whether there are multiple OS or browsers for each User/Device Token combination.

  • Type: Anomaly

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-03-17
  • Author: Scott Dermott, Felicity Robson, Okta, Michael Haag, Bhavin Patel, Splunk
  • ID: 71ad47d1-d6bd-4e0a-b35c-020ad9a6959e

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1539 Steal Web Session Cookie Credential Access
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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`okta` eventType IN (policy.evaluate_sign_on) outcome.result IN (ALLOW, SUCCESS) 
| stats earliest(_time) as _time, values(client.ipAddress) as src_ip, values(client.userAgent.rawUserAgent) as user_agent, values(client.userAgent.os) as userAgentOS_list, values(client.geographicalContext.city) as city, values(client.userAgent.browser) as userAgentBrowser_list, values(device.os_platform) as okta_device_os, dc(client.userAgent.browser) as dc_userAgentBrowser, dc(client.userAgent.os) as dc_userAgentOS, dc(client.ipAddress) as dc_src_ip, values(outcome.reason) as reason by debugContext.debugData.dtHash, user 
| where dc_src_ip>1 AND (dc_userAgentOS>1 OR dc_userAgentBrowser>1) 
| `okta_suspicious_use_of_a_session_cookie_filter`

Macros

The SPL above uses the following Macros:

:information_source: okta_suspicious_use_of_a_session_cookie_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • client.ipAddress
  • client.userAgent.rawUserAgent
  • client.userAgent.os
  • client.geographicalContext.city
  • client.userAgent.browser
  • device.os_platform
  • debugContext.debugData.dtHash
  • actor.alternateId

How To Implement

This detection utilizes logs from Okta Identity Management (IM) environments. It requires the ingestion of OktaIm2 logs through the Splunk Add-on for Okta Identity Cloud (https://splunkbase.splunk.com/app/6553).

Known False Positives

False positives may occur, depending on the organization's size and the configuration of Okta.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
56.0 80 70 A user [$user$] is attempting to use a session cookie from multiple IP addresses or devices. Investigate further to determine if this was authorized.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

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