Detection: Cisco Duo Set User Status to Bypass 2FA
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
3| spath input=target.details path=status output=status
4
5| spath input=old_target.details path=status output=old_status
6
7| search status=Bypass old_status=Active
8
9| rename target.name as user access_device.ip.address as src_ip
10
11| stats count min(_time) as firstTime max(_time) as lastTime
12 BY access_device.browser access_device.browser_version src_ip
13 access_device.location.city access_device.location.country access_device.location.state
14 access_device.os access_device.os_version action.name
15 actor.details actor.name actor.type
16 old_target.details target.details status
17 old_status user
18
19| `security_content_ctime(firstTime)`
20
21| `security_content_ctime(lastTime)`
22
23| `cisco_duo_set_user_status_to_bypass_2fa_filter`
Data Source
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
| ID |
Technique |
Tactic |
| T1556 |
Modify Authentication Process |
Credential Access |
Exploitation
Installation
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 Finding (Notable) |
Yes |
| Rule Title |
%name% |
| Rule Description |
%description% |
| Notable Event Fields |
user, dest |
| Creates Intermediate Finding (Risk Event) |
No |
TTP detections generate a Finding (Notable) and may generate Intermediate Findings (Risk Events) for associated entities.
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
No false positives have been identified at this time.
Associated Analytic Story
Finding
| Title |
Entity Field |
Entity Type |
Risk Score |
| A user $user$ has set their status to bypass 2FA from IP Address - $src_ip$ |
user |
user |
50 |
Threat Objects
| Field |
Type |
| src_ip |
ip_address |
References
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: 6