Library / Windows

prproc.exe

PlayReady Process EXE · Microsoft Corporation

WindowsSysmon-confirmed

OriginalFilename

PlayReady Process EXE

Differs from file name

Gotchas

OriginalFilename doesn't match the file name: a rule using OriginalFileName: prproc.exe never fires.

Query snippets

logsource:
  category: process_creation
  product: windows
detection:
  selection:
    - Image|endswith: '\prproc.exe'
    - OriginalFileName: 'PlayReady Process EXE'
  condition: selection

process_creation logsource. Sigma string matching is case-insensitive.

| tstats summariesonly=false count values(Processes.original_file_name) as original_file_name
    from datamodel=Endpoint.Processes
    where (Processes.original_file_name="PlayReady Process EXE" OR Processes.process_name="prproc.exe")
    by Processes.dest Processes.process_name Processes.process_path Processes.process
| rename Processes.* as *

Endpoint.Processes data model. On raw Sysmon events the field is OriginalFileName.

DeviceProcessEvents
| where ProcessVersionInfoOriginalFileName in~ ("PlayReady Process EXE")
    or FileName =~ "prproc.exe"

Microsoft Defender XDR advanced hunting. in~ and =~ are case-insensitive.

process where event.type == "start" and
  (process.pe.original_file_name in~ ("PlayReady Process EXE") or
   process.name : "prproc.exe")

ECS process.pe.original_file_name is a keyword field: in~ is case-insensitive, Kibana KQL is not.

['playready process exe'].includes(String(OriginalFileName || '').toLowerCase())

Filter expression (JavaScript) for events carrying Sysmon's OriginalFileName field.

Values across builds

OriginalFilename	Builds	Arch	File version	Windows releases	Source	Sysmon
PlayReady Process EXE	1	x64	10.0.26100.1150		Host scan	✓ 1

OriginalFilename

Builds

Arch

File version

Windows releases

Source

Sysmon

PlayReady Process EXE

x64

10.0.26100.1150

Host scan

✓ 1

InternalName: PlayReady Process EXE · Product: Microsoft® Windows® Operating System

All 1 parsed builds

SHA256	Version	Arch	OriginalFilename	Windows releases	Signature	Source	Sysmon
20dedf92ede2…	10.0.26100.1150	x64	PlayReady Process EXE			Host scan	✓

SHA256

Version

Arch

OriginalFilename

Windows releases

Signature

Source

Sysmon

20dedf92ede2…

10.0.26100.1150

x64

PlayReady Process EXE

Host scan

✓

Winbindex builds link to the Microsoft symbol server copy that was hashed and parsed.