rules/cloud/aws_ec2_startup_script_change.yml

title: AWS EC2 Startup Shell Script Change
id: 1ab3c5ed-5baf-417b-bb6b-78ca33f6c3df
status: experimental
author: faloker
date: 2020/02/12
description: Detects changes to the EC2 instance startup script. The shell script will be executed as root/SYSTEM everytime the specific instances are booted up.
references:
    - https://github.com/RhinoSecurityLabs/pacu/blob/master/modules/ec2__startup_shell_script/main.py#L9
logsource:
    service: cloudtrail
detection:
    selection_source:
        - eventSource: ec2.amazonaws.com
    selection_userdata:
        - requestParameters.userData: "*"
    selection_eventname:
        - eventName: ModifyInstanceAttribute
    condition: all of them
level: high
falsepositives:
    - Valid changes to the startup script
tags:
    - attack.t1064
    - attack.t1059
Update rules titles 2020-02-12 23:09:16 +02:00			`title: AWS EC2 Startup Shell Script Change`
Add the rule to detect changes to startup scripts 2020-02-12 22:23:18 +02:00			`id: 1ab3c5ed-5baf-417b-bb6b-78ca33f6c3df`
			`status: experimental`
			`author: faloker`
			`date: 2020/02/12`
			`description: Detects changes to the EC2 instance startup script. The shell script will be executed as root/SYSTEM everytime the specific instances are booted up.`
			`references:`
Correct the indentation 2020-02-12 22:48:46 +02:00			`- https://github.com/RhinoSecurityLabs/pacu/blob/master/modules/ec2__startup_shell_script/main.py#L9`
Add the rule to detect changes to startup scripts 2020-02-12 22:23:18 +02:00			`logsource:`
Correct the indentation 2020-02-12 22:48:46 +02:00			`service: cloudtrail`
Add the rule to detect changes to startup scripts 2020-02-12 22:23:18 +02:00			`detection:`
Correct the indentation 2020-02-12 22:48:46 +02:00			`selection_source:`
			`- eventSource: ec2.amazonaws.com`
			`selection_userdata:`
			`- requestParameters.userData: "*"`
			`selection_eventname:`
			`- eventName: ModifyInstanceAttribute`
			`condition: all of them`
Add the rule to detect changes to startup scripts 2020-02-12 22:23:18 +02:00			`level: high`
			`falsepositives:`
			`- Valid changes to the startup script`
			`tags:`
Correct the indentation 2020-02-12 22:48:46 +02:00			`- attack.t1064`
Initial round of subtechnique updates 2020-06-16 14:46:08 -06:00			`- attack.t1059`