| ID | Technique | Tactic |
|---|---|---|
| T1078.004 | Cloud Accounts | Defense Evasion |
Detection: Abnormally High AWS Instances Launched by User - MLTK
DEPRECATED DETECTION
This detection has been marked as deprecated by the Splunk Threat Research team. This means that it will no longer be maintained or supported. If you have any questions or concerns, please reach out to us at research@splunk.com.
Description
This search looks for AWS CloudTrail events where a user successfully launches an abnormally high number of instances. This search is deprecated and have been translated to use the latest Change Datamodel.
Search
1`cloudtrail` eventName=RunInstances errorCode=success `abnormally_high_aws_instances_launched_by_user___mltk_filter`
2| bucket span=10m _time
3| stats count as instances_launched by _time src_user
4| apply ec2_excessive_runinstances_v1
5| rename "IsOutlier(instances_launched)" as isOutlier
6| where isOutlier=1
Data Source
No data sources specified for this detection.
Macros Used
| Name | Value |
|---|---|
| cloudtrail | sourcetype=aws:cloudtrail |
| abnormally_high_aws_instances_launched_by_user___mltk_filter | search * |
abnormally_high_aws_instances_launched_by_user___mltk_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
MITRE ATT&CK
Kill Chain Phases
NIST
CIS
Threat Actors
KillChainPhase.DELIVERY
KillChainPhase.EXPLOITAITON
KillChainPhase.INSTALLATION
NistCategory.DE_AE
Cis18Value.CIS_13
APT28
APT29
APT33
APT5
Ke3chang
LAPSUS$
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 |
This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.
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 AWS CloudTrail inputs. The threshold value should be tuned to your environment.
Known False Positives
Many service accounts configured within an AWS infrastructure are known to exhibit this behavior. Please adjust the threshold values and filter out service accounts from the output. Always verify if this search alerted on a human user.
Associated Analytic Story
Risk Based Analytics (RBA)
| Risk Message | Risk Score | Impact | Confidence |
|---|---|---|---|
| tbd | 25 | 50 | 50 |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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: 4