ID | Technique | Tactic |
---|
Detection: Detect Spike in AWS Security Hub Alerts for 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 identifies a spike in the number of AWS Security Hub alerts for an AWS IAM User within a 4-hour interval. It leverages AWS Security Hub findings data, calculating the average and standard deviation of alerts to detect significant deviations. This activity is significant as a sudden increase in alerts for a specific user may indicate suspicious behavior or a potential security incident. If confirmed malicious, this could signify an ongoing attack, unauthorized access, or misuse of IAM credentials, potentially leading to data breaches or further exploitation.
Search
1`aws_securityhub_finding` "findings{}.Resources{}.Type"= AwsIamUser
2| rename findings{}.Resources{}.Id as user
3| bucket span=4h _time
4| stats count AS alerts by _time user
5| eventstats avg(alerts) as total_launched_avg, stdev(alerts) as total_launched_stdev
6| eval threshold_value = 2
7| eval isOutlier=if(alerts > total_launched_avg+(total_launched_stdev * threshold_value), 1, 0)
8| search isOutlier=1
9| table _time user alerts
10|`detect_spike_in_aws_security_hub_alerts_for_user_filter`
Data Source
Name | Platform | Sourcetype | Source |
---|---|---|---|
AWS Security Hub | AWS | 'aws:securityhub:finding' |
'aws_securityhub_finding' |
Macros Used
Name | Value |
---|---|
aws_securityhub_finding | sourcetype="aws:securityhub:finding" |
detect_spike_in_aws_security_hub_alerts_for_user_filter | search * |
detect_spike_in_aws_security_hub_alerts_for_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 | True |
Implementation
You must install the AWS App for Splunk (version 5.1.0 or later) and Splunk Add-on for AWS (version 4.4.0 or later), then configure your Security Hub inputs. The threshold_value should be tuned to your environment and schedule these searches according to the bucket span interval.
Known False Positives
None
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Spike in AWS Security Hub alerts for user - $user$ | 25 | 50 | 50 |
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | Not Applicable | N/A | N/A | N/A |
Unit | ❌ Failing | N/A | N/A |
N/A |
Integration | ❌ Failing | N/A | N/A |
N/A |
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: 5