Detection rules › Splunk

Detect AWS Console Login by User from New Country

Status
production
Group by
src, user
Author
Bhavin Patel, Eric McGinnis Splunk
Source
github.com/splunk/security_content

The following analytic identifies AWS console login events by users from a new country. It leverages AWS CloudTrail events and compares them against a lookup file of previously seen users and their login locations. This activity is significant because logins from new countries can indicate potential unauthorized access or compromised accounts. If confirmed malicious, this could lead to unauthorized access to AWS resources, data exfiltration, or further exploitation within the AWS environment.

MITRE ATT&CK coverage

Rule body splunk

name: Detect AWS Console Login by User from New Country
id: 67bd3def-c41c-4bf6-837b-ae196b4257c6
version: 9
creation_date: '2020-04-29'
modification_date: '2026-05-13'
author: Bhavin Patel, Eric McGinnis Splunk
status: production
type: Hunting
description: The following analytic identifies AWS console login events by users from a new country. It leverages AWS CloudTrail events and compares them against a lookup file of previously seen users and their login locations. This activity is significant because logins from new countries can indicate potential unauthorized access or compromised accounts. If confirmed malicious, this could lead to unauthorized access to AWS resources, data exfiltration, or further exploitation within the AWS environment.
data_source:
    - AWS CloudTrail
search: |-
    | tstats earliest(_time) as firstTime latest(_time) as lastTime FROM datamodel=Authentication
      WHERE Authentication.signature=ConsoleLogin
      BY Authentication.user Authentication.src
    | iplocation Authentication.src
    | `drop_dm_object_name(Authentication)`
    | rename Country as justSeenCountry
    | table firstTime lastTime user justSeenCountry
    | join user type=outer [
    | inputlookup previously_seen_users_console_logins
    | rename Country as previouslySeenCountry
    | stats min(firstTime) AS earliestseen
      BY user previouslySeenCountry
    | fields earliestseen user previouslySeenCountry]
    | eval userCountry=if(firstTime >= relative_time(now(), "-24h@h"), "New Country","Previously Seen Country")
    | where userCountry = "New Country"
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | table firstTime lastTime user previouslySeenCountry justSeenCountry userCountry
    | `detect_aws_console_login_by_user_from_new_country_filter`
how_to_implement: You must install and configure the Splunk Add-on for AWS (version 5.1.0 or later) and Enterprise Security 6.2, which contains the required updates to the Authentication data model for cloud use cases. Run the `Previously Seen Users in AWS CloudTrail - Initial` support search only once to create a baseline of previously seen IAM users within the last 30 days. Run `Previously Seen Users in AWS CloudTrail - Update` hourly (or more frequently depending on how often you run the detection searches) to refresh the baselines. You can also provide additional filtering for this search by customizing the `detect_aws_console_login_by_user_from_new_country_filter` macro.
known_false_positives: When a legitimate new user logins for the first time, this activity will be detected. Check how old the account is and verify that the user activity is legitimate.
references: []
analytic_story:
    - Suspicious AWS Login Activities
    - Suspicious Cloud Authentication Activities
    - AWS Identity and Access Management Account Takeover
    - Compromised User Account
asset_type: AWS Instance
mitre_attack_id:
    - T1535
    - T1586.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: threat
baselines:
    - Previously Seen Users in CloudTrail - Initial
    - Previously Seen Users In CloudTrail - Update
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/suspicious_behaviour/abnormally_high_cloud_instances_launched/cloudtrail_behavioural_detections.json
          sourcetype: aws:cloudtrail
          source: aws_cloudtrail
      description: PORTED MANUAL TEST - This search needs the baseline to be run first to create a lookup. It also requires that the timestamps in the dataset be updated.
      test_type: experimental

Stages and Predicates

Stage 1: tstats

| tstats earliest(_time) as firstTime latest(_time) as lastTime FROM datamodel=Authentication
  WHERE Authentication.signature=ConsoleLogin
  BY Authentication.user Authentication.src

Stage 2: search

| iplocation Authentication.src

Stage 3: search

| `drop_dm_object_name(Authentication)`

Stage 4: rename

| rename Country as justSeenCountry

Stage 5: table

| table firstTime lastTime user justSeenCountry

Stage 6: join

| join user type=outer [
| inputlookup previously_seen_users_console_logins
| rename Country as previouslySeenCountry
| stats min(firstTime) AS earliestseen
  BY user previouslySeenCountry
| fields earliestseen user previouslySeenCountry]

Stage 7: eval

| eval userCountry=if(firstTime >= relative_time(now(), "-24h@h"), "New Country","Previously Seen Country")
userCountry =
1."New Country"
-"Previously Seen Country"(default)

Stage 8: where

| where userCountry = "New Country"

Stage 9: search

| `security_content_ctime(firstTime)`

Stage 10: search

| `security_content_ctime(lastTime)`

Stage 11: table

| table firstTime lastTime user previouslySeenCountry justSeenCountry userCountry

Stage 12: search

| `detect_aws_console_login_by_user_from_new_country_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.

FieldKindValues
Authentication.signatureeq
  • ConsoleLogin
userCountryeq
  • "New Country"

Search terms

Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.

StageTerm
2iplocation
2Authentication.src