CloudTrail events from a successful EC2 StopInstan...

Date: 2026-10-07 ID: 85062c20-6b3e-438a-a17c-1d953c2dedb4 Author: Maria Jose Erquiaga, Splunk Environment: aws_ec2_test_instance Directory: Unknown

Description

CloudTrail events from a successful EC2 StopInstances request followed by a successful ModifyInstanceAttribute request targeting userData on the same instance, by the same IAM principal, within one hour. Modification of user data does not by itself confirm that the script executed.

MITRE ATT&CK Techniques

ID	Technique	Tactic
T1578.005	Modify Cloud Compute Configurations	Defense Impairment

Environment Details

Field	Value
Environment	aws_ec2_test_instance
Directory	Unknown
Test Date	2026-10-07

Datasets

The following datasets were collected during this attack simulation:

Aws_ec2_startup_script_modification-Json

Path: /datasets/attack_techniques/T1578.005/aws_ec2_startup_script_modification/aws_ec2_startup_script_modification.json
Sourcetype: aws:cloudtrail
Source: aws_cloudtrail

No specific detections currently use this attack data for testing. However, you can find related detections and analytics in our security content repository.

Usage Instructions

Replay with Splunk Attack Data

Replay attack data with replay.py from Splunk Attack Data.

1python replay.py --dataset /datasets/attack_techniques/T1578.005/aws_ec2_startup_script_modification/aws_ec2_startup_script_modification.json --index attack_data

Manual Import

Download the dataset files from the paths listed above
Configure your Splunk instance with the appropriate sourcetypes
Import the logs using the Splunk Add Data wizard

Find more detections and analytics for this attack technique in our security content repository.

Source: GitHub | Version: 1.0