LoFP LoFP / false positives in pdf file opened pdf viewer having legitimate url link, however filter as needed.

Techniques

Sample rules

Description

The following analytic detects suspicious PDF viewer processes spawning browser application child processes. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and parent process names. This activity is significant as it may indicate a PDF spear-phishing attempt where a malicious URL link is executed, leading to potential payload download. If confirmed malicious, this could allow attackers to execute code, escalate privileges, or persist in the environment by exploiting the user’s browser to connect to a malicious site.

Detection logic


| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.parent_process_name  IN ("AcroRd32.exe", "FoxitPDFReader.exe") Processes.process_name IN ("firefox.exe", "chrome.exe", "iexplore.exe")
  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)`

| `windows_phishing_pdf_file_executes_url_link_filter`