Detection: Cisco Duo Set User Status to Bypass 2FA

Updated Date: 2025-07-08 ID: 8728d224-9cd5-4aa7-b75f-f8520a569979 Author: Patrick Bareiss, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects instances where a Duo user's status is changed to "Bypass" for 2FA, specifically when the previous status was "Active." This behavior is identified by analyzing Duo activity logs for user update actions, extracting the status transitions, and filtering for cases where a user is set to bypass multi-factor authentication. This is a critical event for a Security Operations Center (SOC) to monitor, as bypassing 2FA significantly weakens account security and may indicate malicious insider activity or account compromise. Attackers or unauthorized administrators may exploit this change to disable strong authentication controls, increasing the risk of unauthorized access to sensitive systems and data. Early detection of such changes enables rapid investigation and response, helping to prevent potential breaches and limit the impact of credential-based attacks.

Search

1`cisco_duo_activity` action.name=user_update 
2| spath input=target.details path=status output=status 
3| spath input=old_target.details path=status output=old_status 
4| search status=Bypass old_status=Active 
5| rename target.name as user access_device.ip.address as src_ip 
6| stats count min(_time) as firstTime max(_time) as lastTime by access_device.browser access_device.browser_version src_ip access_device.location.city access_device.location.country access_device.location.state access_device.os access_device.os_version action.name actor.details actor.name actor.type old_target.details target.details status old_status user 
7| `security_content_ctime(firstTime)` 
8| `security_content_ctime(lastTime)` 
9| `cisco_duo_set_user_status_to_bypass_2fa_filter`

Data Source

Name	Platform	Sourcetype	Source
Cisco Duo Administrator	N/A	`'cisco:duo:administrator'`	`'cisco_duo'`

Macros Used

Name	Value
cisco_duo_activity	`sourcetype=cisco:duo:activity`
cisco_duo_set_user_status_to_bypass_2fa_filter	`search *`

cisco_duo_set_user_status_to_bypass_2fa_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

Exploitation

Installation

DE.CM

CIS 10

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 Duo activity logs to be ingested using the Cisco Security Cloud App (https://splunkbase.splunk.com/app/7404).

Known False Positives

unknown

Associated Analytic Story

Cisco Duo Suspicious Activity

Risk Based Analytics (RBA)

Risk Message:

A user $user$ has set their status to bypass 2FA from IP Address - $src_ip$

Risk Object	Risk Object Type	Risk Score	Threat Objects
user	user	48	src_ip

References

https://splunkbase.splunk.com/app/7404

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`duo`	`cisco:duo:activity`
Integration	✅ Passing	Dataset	`duo`	`cisco:duo:activity`

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: 1