ID | Technique | Tactic |
---|
Detection: Detect Spike in AWS Security Hub Alerts for EC2 Instance
Description
The following analytic identifies a spike in the number of AWS Security Hub alerts for an EC2 instance within a 4-hour interval. It leverages AWS Security Hub findings data, calculating the average and standard deviation of alerts to detect anomalies. This activity is significant for a SOC as a sudden increase in alerts may indicate potential security incidents or misconfigurations requiring immediate attention. If confirmed malicious, this could signify an ongoing attack, leading to unauthorized access, data exfiltration, or disruption of services on the affected EC2 instance.
Search
1`aws_securityhub_finding` "Resources{}.Type"=AWSEC2Instance
2| bucket span=4h _time
3| stats count AS alerts values(Title) as Title values(Types{}) as Types values(vendor_account) as vendor_account values(vendor_region) as vendor_region values(severity) as severity by _time dest
4| eventstats avg(alerts) as total_alerts_avg, stdev(alerts) as total_alerts_stdev
5| eval threshold_value = 3
6| eval isOutlier=if(alerts > total_alerts_avg+(total_alerts_stdev * threshold_value), 1, 0)
7| search isOutlier=1
8| table _time dest alerts Title Types vendor_account vendor_region severity isOutlier total_alerts_avg
9| `detect_spike_in_aws_security_hub_alerts_for_ec2_instance_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
AWS Security Hub | AWS | 'aws:securityhub:finding' |
'aws_securityhub_finding' |
N/A |
Macros Used
Name | Value |
---|---|
aws_securityhub_finding | sourcetype="aws:securityhub:finding" |
detect_spike_in_aws_security_hub_alerts_for_ec2_instance_filter | search * |
detect_spike_in_aws_security_hub_alerts_for_ec2_instance_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 with title $Title$ for EC2 instance $dest$ | 15 | 30 | 50 |
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | aws_securityhub_finding |
aws:securityhub:finding |
Integration | ✅ Passing | Dataset | aws_securityhub_finding |
aws:securityhub:finding |
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