Detection: GCP Detect gcploit framework

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.

Updated Date: 2024-10-17 ID: a1c5a85e-a162-410c-a5d9-99ff639e5a52 Author: Rod Soto, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies the use of the GCPloit exploitation framework within Google Cloud Platform (GCP). It detects specific GCP Pub/Sub messages with a function timeout of 539 seconds, which is indicative of GCPloit activity. This detection is significant as GCPloit can be used to escalate privileges and facilitate lateral movement from compromised high-privilege accounts. If confirmed malicious, this activity could allow attackers to gain unauthorized access, escalate their privileges, and move laterally within the GCP environment, potentially compromising sensitive data and critical resources.

Search

1`google_gcp_pubsub_message` data.protoPayload.request.function.timeout=539s 
2| table src src_user data.resource.labels.project_id data.protoPayload.request.function.serviceAccountEmail data.protoPayload.authorizationInfo{}.permission data.protoPayload.request.location http_user_agent 
3| `gcp_detect_gcploit_framework_filter`

Data Source

No data sources specified for this detection.

Macros Used

Name	Value
google_gcp_pubsub_message	`sourcetype="google:gcp:pubsub:message"`
gcp_detect_gcploit_framework_filter	`search *`

gcp_detect_gcploit_framework_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

ID	Technique	Tactic
T1078	Valid Accounts	Defense Evasion

KillChainPhase.DELIVERY

KillChainPhase.EXPLOITAITON

KillChainPhase.INSTALLATION

NistCategory.DE_CM

Cis18Value.CIS_10

APT18

APT28

APT29

APT33

APT39

APT41

Akira

Axiom

Carbanak

Chimera

Cinnamon Tempest

Dragonfly

FIN10

FIN4

FIN5

FIN6

FIN7

FIN8

Fox Kitten

GALLIUM

INC Ransom

Indrik Spider

Ke3chang

LAPSUS$

Lazarus Group

Leviathan

OilRig

POLONIUM

PittyTiger

Play

Sandworm Team

Silence

Silent Librarian

Star Blizzard

Suckfly

Threat Group-3390

Volt Typhoon

Wizard Spider

menuPass

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 Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

You must install splunk GCP add-on. This search works with gcp:pubsub:message logs

Known False Positives

Payload.request.function.timeout value can possibly be match with other functions or requests however the source user and target request account may indicate an attempt to move laterally accross acounts or projects

Associated Analytic Story

GCP Cross Account Activity

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.

References

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: 3