mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Bhavin Patel
95 lines
4.0 KiB
YAML
95 lines
4.0 KiB
YAML
name: Detect HTML Help Renamed
|
|
id: 62fed254-513b-460e-953d-79771493a9f3
|
|
version: 4
|
|
date: '2022-04-07'
|
|
author: Michael Haag, Splunk
|
|
status: production
|
|
type: Hunting
|
|
description: The following analytic identifies a renamed instance of hh.exe (HTML
|
|
Help) executing a Compiled HTML Help (CHM). This particular technique will load
|
|
Windows script code from a compiled help file. CHM files may contain nearly any
|
|
file type embedded, but only execute html/htm. Upon a successful execution, the
|
|
following script engines may be used for execution - JScript, VBScript, VBScript.Encode,
|
|
JScript.Encode, JScript.Compact. Analyst may identify vbscript.dll or jscript.dll
|
|
loading into hh.exe upon execution. The "htm" and "html" file extensions were the
|
|
only extensions observed to be supported for the execution of Shortcut commands
|
|
or WSH script code. During investigation, identify script content origination. Validate
|
|
it is the legitimate version of hh.exe by reviewing the PE metadata. hh.exe is natively
|
|
found in C:\Windows\system32 and C:\Windows\syswow64.
|
|
data_source:
|
|
- Sysmon Event ID 1
|
|
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
|
|
as lastTime from datamodel=Endpoint.Processes where Processes.process_name!=hh.exe
|
|
AND Processes.original_file_name=HH.EXE by Processes.dest Processes.user Processes.parent_process_name
|
|
Processes.original_file_name Processes.process_name Processes.process Processes.process_id
|
|
Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`
|
|
| `security_content_ctime(lastTime)` | `detect_html_help_renamed_filter`'
|
|
how_to_implement: The detection is based on data that originates from Endpoint Detection
|
|
and Response (EDR) agents. These agents are designed to provide security-related
|
|
telemetry from the endpoints where the agent is installed. To implement this search,
|
|
you must ingest logs that contain the process GUID, process name, and parent process.
|
|
Additionally, you must ingest complete command-line executions. These logs must
|
|
be processed using the appropriate Splunk Technology Add-ons that are specific to
|
|
the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint`
|
|
data model. Use the Splunk Common Information Model (CIM) to normalize the field
|
|
names and speed up the data modeling process.
|
|
known_false_positives: Although unlikely a renamed instance of hh.exe will be used
|
|
legitimately, filter as needed.
|
|
references:
|
|
- https://attack.mitre.org/techniques/T1218/001/
|
|
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.001/T1218.001.md
|
|
- https://lolbas-project.github.io/lolbas/Binaries/Hh/
|
|
tags:
|
|
analytic_story:
|
|
- Suspicious Compiled HTML Activity
|
|
- Living Off The Land
|
|
asset_type: Endpoint
|
|
confidence: 100
|
|
impact: 80
|
|
message: The following $process_name$ has been identified as renamed, spawning from $parent_process_name$ on $dest$ executed by $user$
|
|
mitre_attack_id:
|
|
- T1218
|
|
- T1218.001
|
|
observable:
|
|
- name: user
|
|
type: User
|
|
role:
|
|
- Victim
|
|
- name: dest
|
|
type: Hostname
|
|
role:
|
|
- Victim
|
|
- name: parent_process_name
|
|
type: Process
|
|
role:
|
|
- Parent Process
|
|
- name: process_name
|
|
type: Process
|
|
role:
|
|
- Child Process
|
|
product:
|
|
- Splunk Enterprise
|
|
- Splunk Enterprise Security
|
|
- Splunk Cloud
|
|
required_fields:
|
|
- _time
|
|
- Processes.dest
|
|
- Processes.user
|
|
- Processes.parent_process_name
|
|
- Processes.parent_process
|
|
- Processes.original_file_name
|
|
- Processes.process_name
|
|
- Processes.process
|
|
- Processes.process_id
|
|
- Processes.parent_process_path
|
|
- Processes.process_path
|
|
- Processes.parent_process_id
|
|
risk_score: 80
|
|
security_domain: endpoint
|
|
tests:
|
|
- name: True Positive Test
|
|
attack_data:
|
|
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1218.001/atomic_red_team/windows-sysmon.log
|
|
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
|
|
sourcetype: xmlwineventlog
|