Detection: AWS Multiple Users Failing To Authenticate From Ip

Updated Date: 2026-05-13 ID: 71e1fb89-dd5f-4691-8523-575420de4630 Author: Bhavin Patel Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic identifies a single source IP failing to authenticate into the AWS Console with 30 unique valid users within 10 minutes. It leverages CloudTrail logs to detect multiple failed login attempts from the same IP address. This behavior is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain unauthorized access or elevate privileges by trying common passwords across many accounts. If confirmed malicious, this activity could lead to unauthorized access, data breaches, or further exploitation within the AWS environment.

Search

 1`cloudtrail` eventName=ConsoleLogin action=failure
 2  
 3| bucket span=10m _time
 4  
 5| rename user_name as user
 6  
 7| stats  dc(user) AS unique_accounts values(user) as user values(user_agent) as user_agent
 8    BY _time, src, signature,
 9       dest, vendor_account, vendor_region,
10       vendor_product
11  
12| where unique_accounts>30
13  
14| `security_content_ctime(firstTime)`
15  
16| `security_content_ctime(lastTime)`
17  
18| `aws_multiple_users_failing_to_authenticate_from_ip_filter`

Data Source

Name	Platform	Sourcetype	Source
AWS CloudTrail ConsoleLogin	AWS	`'aws:cloudtrail'`	`'aws_cloudtrail'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
aws_multiple_users_failing_to_authenticate_from_ip_filter	`search *`

aws_multiple_users_failing_to_authenticate_from_ip_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
T1110.003	Password Spraying	Credential Access
T1110.004	Credential Stuffing	Credential Access

Exploitation

DE.AE

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 Finding (Notable)	No
Creates Intermediate Finding (Risk Event)	Yes

Anomaly detections generate Intermediate Findings (Risk Events). They do not generate a Finding (Notable) directly.

Implementation

You must install Splunk Add-on for AWS in order to ingest Cloudtrail. We recommend the users to try different combinations of the bucket span time and the tried account threshold to tune this search according to their environment.

Known False Positives

No known false postives for this detection. Please review this alert

Associated Analytic Story

Intermediate Findings

Message	Entity Field	Entity Type	Risk Score
Multiple failed console login attempts (Count: $unique_accounts$) against users from IP Address - $src$	user	user	20

Threat Objects

Field	Type
src	ip_address

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`aws_cloudtrail`	`aws:cloudtrail`
Integration	✅ Passing	Dataset	`aws_cloudtrail`	`aws:cloudtrail`

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: 11