Detection: Headless Browser Mockbin or Mocky Request

Updated Date: 2024-09-30 ID: 94fc85a1-e55b-4265-95e1-4b66730e05c0 Author: Michael Haag, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects headless browser activity accessing mockbin.org or mocky.io. It identifies processes with the "--headless" and "--disable-gpu" command line arguments, along with references to mockbin.org or mocky.io. This behavior is significant as headless browsers are often used for automated tasks, including malicious activities like web scraping or automated attacks. If confirmed malicious, this activity could indicate an attempt to bypass traditional browser security measures, potentially leading to data exfiltration or further exploitation of web applications.

Search

1
2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process="*--headless*" AND Processes.process="*--disable-gpu*" AND (Processes.process="*mockbin.org/*" OR Processes.process="*mocky.io/*")) by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id 
3| `drop_dm_object_name(Processes)` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `headless_browser_mockbin_or_mocky_request_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	N/A	`'crowdstrike:events:sensor'`	`'crowdstrike'`
Sysmon EventID 1	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`
Windows Event Log Security 4688	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Security'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
headless_browser_mockbin_or_mocky_request_filter	`search *`

headless_browser_mockbin_or_mocky_request_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
T1564.003	Hidden Window	Defense Evasion

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

APT19

APT28

APT3

APT32

CopyKittens

DarkHydrus

Deep Panda

Gamaredon Group

Gorgon Group

Higaisa

Kimsuky

Magic Hound

Nomadic Octopus

ToddyCat

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

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Processes node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.

Known False Positives

False positives are not expected with this detection, unless within the organization there is a legitimate need for headless browsing accessing mockbin.org or mocky.io.

Associated Analytic Story

Forest Blizzard

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Headless browser activity accessing mockbin.org or mocky.io detected on $dest$ by $user$.	56	80	70

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	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`

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