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Description

The following analytic identifies a successful Console Login authentication event against an AWS IAM user for an account without Multi-Factor Authentication enabled. This could be evidence of a misconfiguration, a policy violation or an account take over attempt that should be investigated

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2022-10-04
  • Author: Bhavin Patel, Splunk
  • ID: a520b1fe-cc9e-4f56-b762-18354594c52f

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1586 Compromise Accounts Resource Development
T1586.003 Cloud Accounts Resource Development
T1078 Valid Accounts Defense Evasion, Persistence, Privilege Escalation, Initial Access
T1078.004 Cloud Accounts Defense Evasion, Persistence, Privilege Escalation, Initial Access
Kill Chain Phase
  • Weaponization
  • Exploitation
  • Installation
  • Delivery
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`cloudtrail` eventName= ConsoleLogin errorCode=success "additionalEventData.MFAUsed"=No 
| stats count min(_time) as firstTime max(_time) as lastTime by src eventName eventSource aws_account_id errorCode additionalEventData.MFAUsed userAgent eventID awsRegion user_name userIdentity.arn 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `aws_successful_single_factor_authentication_filter`

Macros

The SPL above uses the following Macros:

:information_source: aws_successful_single-factor_authentication_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • src
  • eventName
  • eventSource
  • aws_account_id
  • errorCode
  • additionalEventData.MFAUsed
  • userAgent
  • eventID
  • awsRegion
  • user_name
  • userIdentity.arn

How To Implement

The Splunk AWS Add-on is required to utilize this data. The search requires AWS Cloudtrail logs.

Known False Positives

It is possible that some accounts do not have MFA enabled for the AWS account however its agaisnt the best practices of securing AWS.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
64.0 80 80 User $user_name$ has successfully logged into an AWS Console without Multi-Factor Authentication from $src$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 1