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Description

The following analytic identifies a successful single-factor authentication event against Azure Active Directory. It leverages Azure SignInLogs data, specifically focusing on events where single-factor authentication succeeded. This activity is significant as it may indicate a misconfiguration, policy violation, or potential account takeover attempt. If confirmed malicious, an attacker could gain unauthorized access to the account, potentially leading to data breaches, privilege escalation, or further exploitation within the environment.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Authentication
  • Last Updated: 2024-05-23
  • Author: Mauricio Velazco, Gowthamaraj Rajendran, Splunk
  • ID: a560e7f6-1711-4353-885b-40be53101fcd

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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 `azure_monitor_aad` category=SignInLogs properties.authenticationRequirement=singleFactorAuthentication properties.authenticationDetails{}.succeeded=true 
| rename properties.* as * 
| stats count min(_time) as firstTime max(_time) as lastTime values(user) as user by src_ip, appDisplayName, authenticationRequirement 
| `azure_ad_successful_single_factor_authentication_filter`

Macros

The SPL above uses the following Macros:

:information_source: azure_ad_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.

  • _time
  • category
  • properties.authenticationRequirement
  • properties.authenticationDetails
  • user
  • src_ip
  • properties.appDisplayName

How To Implement

You must install the latest version of Splunk Add-on for Microsoft Cloud Services from Splunkbase (https://splunkbase.splunk.com/app/3110/#/details). You must be ingesting Azure Active Directory events into your Splunk environment through an EventHub. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the Signin log category.

Known False Positives

Although not recommended, certain users may be required without multi-factor authentication. Filter as needed

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
45.0 50 90 Successful authentication for user $user$ without MFA

: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: 3