Detection: Okta Multi-Factor Authentication Disabled

Updated Date: 2024-09-30 ID: 7c0348ce-bdf9-45f6-8a57-c18b5976f00a Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies an attempt to disable multi-factor authentication (MFA) for an Okta user. It leverages OktaIM2 logs to detect when the 'user.mfa.factor.deactivate' command is executed. This activity is significant because disabling MFA can allow an adversary to maintain persistence within the environment using a compromised valid account. If confirmed malicious, this action could enable attackers to bypass additional security layers, potentially leading to unauthorized access to sensitive information and prolonged undetected presence in the network.

1
2| tstats `security_content_summariesonly` count max(_time) as lastTime, min(_time) as firstTime from datamodel=Change where sourcetype="OktaIM2:log" All_Changes.object_category=User AND All_Changes.action=modified All_Changes.command=user.mfa.factor.deactivate by All_Changes.user All_Changes.result All_Changes.command sourcetype All_Changes.src 
3| `drop_dm_object_name("All_Changes")` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `okta_multi_factor_authentication_disabled_filter`

Data Source

Name Platform Sourcetype Source
Okta N/A 'OktaIM2:log' 'Okta'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
okta_multi_factor_authentication_disabled_filter search *
okta_multi_factor_authentication_disabled_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1556 Modify Authentication Process Credential Access
T1556.006 Multi-Factor Authentication Defense Evasion
KillChainPhase.EXPLOITAITON
KillChainPhase.INSTALLATION
NistCategory.DE_CM
Cis18Value.CIS_10
FIN13
Scattered Spider

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

The analytic leverages Okta OktaIm2 logs to be ingested using the Splunk Add-on for Okta Identity Cloud (https://splunkbase.splunk.com/app/6553).

Known False Positives

Legitimate use case may require for users to disable MFA. Filter lightly and monitor for any unusual activity.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
MFA was disabled for User [$user$] initiated by [$src$]. Investigate further to determine if this was authorized. 30 50 60
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset Okta OktaIM2:log
Integration ✅ Passing Dataset Okta OktaIM2:log

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

Source: GitHub | Version: 4