AWS Successful Console Authentication From Multiple IPs
Description
The following analytic detects an AWS account successfully authenticating from multiple unique IP addresses within a 5-minute window. It leverages AWS CloudTrail logs, specifically monitoring ConsoleLogin events and counting distinct source IPs. This behavior is significant as it may indicate compromised credentials, potentially from a phishing attack, being used concurrently by an adversary and a legitimate user. If confirmed malicious, this activity could allow unauthorized access to corporate resources, leading to data breaches or further exploitation within the AWS environment.
Query · spl
`cloudtrail` eventName = ConsoleLogin
| bin span=5m _time
| rename user_name as user
| stats dc(src) as distinct_ip_count values(src) as src values(user_agent) as user_agent values(dest) as dest
BY _time, user, signature,
vendor_account, vendor_region, vendor_product
| where distinct_ip_count>1
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `aws_successful_console_authentication_from_multiple_ips_filter`
Implementation guide
You must install Splunk AWS add on and Splunk App for AWS. This search works when AWS CloudTrail events are normalized use the Authentication datamodel.
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.