Detection: Okta Authentication Failed During MFA Challenge

Updated Date: 2024-09-30 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.

Search

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
Okta	N/A	`'OktaIM2:log'`	`'Okta'`

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

INC Ransom

Indrik Spider

Ke3chang

LAPSUS$

Lazarus Group

Leviathan

OilRig

POLONIUM

PittyTiger

Play

Sandworm Team

Silence

Silent Librarian

Star Blizzard

Suckfly

Threat Group-3390

Volt Typhoon

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

Okta Account Takeover

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: 3