LoFP LoFP / administrators may use this command. filter as needed.

Techniques

Sample rules

Modify ACL permission To Files Or Folder

Description

The following analytic detects the modification of ACL permissions to files or folders, making them accessible to everyone or to system account. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes like “cacls.exe,” “icacls.exe,” and “xcacls.exe” with specific command-line arguments. This activity is significant as it may indicate an adversary attempting to evade ACLs or access protected files. If confirmed malicious, this could allow unauthorized access to sensitive data, potentially leading to data breaches or further system compromise.

Detection logic


| tstats `security_content_summariesonly` count 
  min(_time) as firstTime 
  max(_time) as lastTime
  values(Processes.process) as process
  values(Processes.process_id) as process_id 
from datamodel=Endpoint.Processes where 
  Processes.process_name IN ("icacls.exe", "cacls.exe", "xcacls.exe") 
  Processes.process IN ("*/grant*", "*/g:*", "*/g *") 
  Processes.process IN ("* Everyone:*", "* SYSTEM:*", "* S-1-1-0:*")
by Processes.action Processes.dest Processes.original_file_name Processes.parent_process 
Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id 
Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec 
Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level 
Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product

| `drop_dm_object_name(Processes)` 

| `security_content_ctime(firstTime)` 

| `security_content_ctime(lastTime)`

| `modify_acl_permission_to_files_or_folder_filter`