Detection: Okta Authentication Failed During MFA Challenge

Updated Date: 2024-05-29 ID: e2b99e7d-d956-411a-a120-2b14adfdde93 Author: Bhavin Patel, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies failed authentication attempts during the Multi-Factor Authentication (MFA) challenge in an Okta tenant. It uses the Authentication datamodel to detect specific failed events where the authentication signature is user.authentication.auth_via_mfa. This activity is significant as it may indicate an adversary attempting to authenticate with compromised credentials on an account with MFA enabled. If confirmed malicious, this could suggest an ongoing attempt to bypass MFA protections, potentially leading to unauthorized access and further compromise of the affected account.

1
2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime  values(Authentication.app) as app values(Authentication.reason) as reason values(Authentication.signature) as signature  values(Authentication.method) as method  from datamodel=Authentication where  Authentication.signature=user.authentication.auth_via_mfa Authentication.action = failure by _time Authentication.src Authentication.user Authentication.dest Authentication.action 
3| `drop_dm_object_name("Authentication")` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)`
6| iplocation src 
7| `okta_authentication_failed_during_mfa_challenge_filter`

Data Source

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

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
okta_authentication_failed_during_mfa_challenge_filter search *
okta_authentication_failed_during_mfa_challenge_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
T1586 Compromise Accounts Resource Development
T1586.003 Cloud Accounts Resource Development
T1078 Valid Accounts Defense Evasion
T1078.004 Cloud Accounts Initial Access
T1621 Multi-Factor Authentication Request Generation Persistence
KillChainPhase.DELIVERY
KillChainPhase.EXPLOITAITON
KillChainPhase.INSTALLATION
KillChainPhase.WEAPONIZATION
NistCategory.DE_CM
Cis18Value.CIS_10
APT29
APT18
APT28
APT29
APT33
APT39
APT41
Akira
Axiom
Carbanak
Chimera
Cinnamon Tempest
Dragonfly
FIN10
FIN4
FIN5
FIN6
FIN7
FIN8
Fox Kitten
GALLIUM
Ke3chang
LAPSUS$
Lazarus Group
Leviathan
OilRig
POLONIUM
PittyTiger
Sandworm Team
Silence
Silent Librarian
Suckfly
Threat Group-3390
Wizard Spider
menuPass
APT28
APT29
APT33
APT5
Ke3chang
LAPSUS$
APT29
LAPSUS$
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

A user may have accidentally entered the wrong credentials during the MFA challenge. If the user is new to MFA, they may have trouble authenticating. Ensure that the user is aware of the MFA process and has the correct credentials.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
A user [$user$] has failed to authenticate via MFA from IP Address - [$src$]" 48 80 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_log OktaIM2:log
Integration ✅ Passing Dataset okta_log 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: 2