ID | Technique | Tactic |
---|---|---|
T1586 | Compromise Accounts | Resource Development |
T1586.003 | Cloud Accounts | Resource Development |
T1552 | Unsecured Credentials | Credential Access |
Detection: Detect AWS Console Login by New User
EXPERIMENTAL DETECTION
This detection status is set to experimental. The Splunk Threat Research team has not yet fully tested, simulated, or built comprehensive datasets for this detection. As such, this analytic is not officially supported. If you have any questions or concerns, please reach out to us at research@splunk.com.
Description
The following analytic detects AWS console login events by new users. It leverages AWS CloudTrail events and compares them against a lookup file of previously seen users based on ARN values. This detection is significant because a new user logging into the AWS console could indicate the creation of new accounts or potential unauthorized access. If confirmed malicious, this activity could lead to unauthorized access to AWS resources, data exfiltration, or further exploitation within the cloud environment.
Search
1
2| tstats earliest(_time) as firstTime latest(_time) as lastTime from datamodel=Authentication where Authentication.signature=ConsoleLogin by Authentication.user
3| `drop_dm_object_name(Authentication)`
4| join user type=outer [
5| inputlookup previously_seen_users_console_logins
6| stats min(firstTime) as earliestseen by user]
7| eval userStatus=if(earliestseen >= relative_time(now(), "-24h@h") OR isnull(earliestseen), "First Time Logging into AWS Console", "Previously Seen User")
8| where userStatus="First Time Logging into AWS Console"
9| `security_content_ctime(firstTime)`
10| `security_content_ctime(lastTime)`
11| `detect_aws_console_login_by_new_user_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
AWS CloudTrail | AWS | 'aws:cloudtrail' |
'aws_cloudtrail' |
N/A |
Macros Used
Name | Value |
---|---|
security_content_ctime | convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$) |
detect_aws_console_login_by_new_user_filter | search * |
detect_aws_console_login_by_new_user_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Risk Event | False |
Implementation
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 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 CloudTrail - Update
hourly (or more frequently depending on how often you run the detection searches) to refresh the baselines.
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.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
User $user$ is logging into the AWS console for the first time | 30 | 50 | 60 |
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | Not Applicable | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | aws_cloudtrail |
aws:cloudtrail |
Integration | ✅ Passing | Dataset | aws_cloudtrail |
aws:cloudtrail |
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: GitHub | Version: 4