Detection rules › Splunk
AWS Multiple Failed MFA Requests For User
The following analytic identifies multiple failed multi-factor authentication (MFA) requests to an AWS Console for a single user. It leverages AWS CloudTrail logs, specifically the additionalEventData field, to detect more than 10 failed MFA prompts within 5 minutes. This activity is significant as it may indicate an adversary attempting to bypass MFA by bombarding the user with repeated authentication requests. If confirmed malicious, this could lead to unauthorized access to the AWS environment, potentially compromising sensitive data and resources.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Resource Development | T1586.003 Compromise Accounts: Cloud Accounts |
| Credential Access | T1621 Multi-Factor Authentication Request Generation |
Rules detecting the same action
Other rules on this platform that filter on the same API call or operation.
- AWS Console Login (Panther)
- AWS Console Login Failed During MFA Challenge (Splunk)
- AWS ConsoleLogin Failed Authentication (Sigma)
- AWS CreateLoginProfile (Splunk)
- AWS Credential Access Failed Login (Splunk)
- AWS High Number Of Failed Authentications For User (Splunk)
- AWS High Number Of Failed Authentications From Ip (Splunk)
- AWS Multiple Users Failing To Authenticate From Ip (Splunk)
Rule body splunk
name: AWS Multiple Failed MFA Requests For User
id: 1fece617-e614-4329-9e61-3ba228c0f353
version: 11
creation_date: '2022-10-03'
modification_date: '2026-05-13'
author: Bhavin Patel
status: production
type: Anomaly
description: The following analytic identifies multiple failed multi-factor authentication (MFA) requests to an AWS Console for a single user. It leverages AWS CloudTrail logs, specifically the `additionalEventData` field, to detect more than 10 failed MFA prompts within 5 minutes. This activity is significant as it may indicate an adversary attempting to bypass MFA by bombarding the user with repeated authentication requests. If confirmed malicious, this could lead to unauthorized access to the AWS environment, potentially compromising sensitive data and resources.
data_source:
- AWS CloudTrail ConsoleLogin
search: |-
`cloudtrail` eventName= ConsoleLogin "additionalEventData.MFAUsed"=Yes errorMessage="Failed authentication"
| bucket span=5m _time
| rename user_name as user
| stats dc(_raw) as mfa_prompts min(_time) as firstTime max(_time) as lastTime values(user_agent) as user_agent values(src) as src values(dest) as dest
BY _time user signature
vendor_account vendor_region vendor_product
errorMessage
| where mfa_prompts > 10
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `aws_multiple_failed_mfa_requests_for_user_filter`
how_to_implement: The Splunk AWS Add-on is required to utilize this data. The search requires AWS CloudTrail logs.
known_false_positives: Multiple Failed MFA requests may also be a sign of authentication or application issues. Filter as needed.
references:
- https://attack.mitre.org/techniques/T1621/
- https://aws.amazon.com/what-is/mfa/
drilldown_searches:
- name: View the detection results for - "$user$"
search: '%original_detection_search% | search user = "$user$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$user$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset: 7d
latest_offset: "0"
intermediate_findings:
entities:
- field: user
type: user
score: 20
message: User $user$ is seen to have high number of MFA prompt failures within a short period of time.
threat_objects:
- field: src
type: ip_address
analytic_story:
- AWS Identity and Access Management Account Takeover
asset_type: AWS Account
mitre_attack_id:
- T1586.003
- T1621
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
category: cloud
security_domain: threat
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1621/aws_failed_mfa/cloudtrail.json
sourcetype: aws:cloudtrail
source: aws_cloudtrail
test_type: unit
Stages and Predicates
Stage 1: search
`cloudtrail` eventName= ConsoleLogin "additionalEventData.MFAUsed"=Yes errorMessage="Failed authentication"
Stage 2: bucket
| bucket span=5m _time
Stage 3: rename
| rename user_name as user
Stage 4: stats
| stats dc(_raw) as mfa_prompts min(_time) as firstTime max(_time) as lastTime values(user_agent) as user_agent values(src) as src values(dest) as dest
BY _time user signature
vendor_account vendor_region vendor_product
errorMessage
Stage 5: where
| where mfa_prompts > 10
Stage 6: search
| `security_content_ctime(firstTime)`
Stage 7: search
| `security_content_ctime(lastTime)`
Stage 8: search
| `aws_multiple_failed_mfa_requests_for_user_filter`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
"additionalEventData.MFAUsed" | eq |
|
errorMessage | eq |
|
eventName | eq |
|
mfa_prompts | gt |
|
sourcetype | eq |
|