Azure AD Successful Authentication From Different Ips
Description
The following analytic detects an Azure AD account successfully authenticating from multiple unique IP addresses within a 30-minute window. It leverages Azure AD SignInLogs to identify instances where the same user logs in from different IPs in a short time frame. This behavior is significant as it may indicate compromised credentials being used by an adversary, potentially following a phishing attack. If confirmed malicious, this activity could allow unauthorized access to corporate resources, leading to data breaches or further exploitation within the network.
Query · spl
`azure_monitor_aad` properties.authenticationDetails{}.succeeded=true category=SignInLogs
| rename properties.* as *
| bucket span=30m _time
| fillnull
| stats count min(_time) as firstTime max(_time) as lastTime dc(src) AS unique_ips values(dest) as dest values(src) as src
BY user vendor_account vendor_product
signature
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| where unique_ips > 1
| `azure_ad_successful_authentication_from_different_ips_filter`
Implementation guide
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
- A user with successful authentication events from different Ips may also represent the legitimate use of more than one device. Filter as needed and/or customize the threshold to fit your environment.
Analyst notes
Known false positives: A user with successful authentication events from different Ips may also represent the legitimate use of more than one device. Filter as needed and/or customize the threshold to fit your environment.