Windows File Events: Legitimate Applications Writing Executables to Uncommon Locations
Alerts when selected Windows binaries write files to typically uncommon directories such as Temp, ProgramData, AppData, or system areas.
- Product
- windows
- Category
- file_event
- Author
- Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ), DRL 1.1
- Published
- 2025-12-10
- Updated
- 2026-07-31
ATT&CK techniques
Defense Evasion → C2Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
Exfiltration
Impact
What it detects
This rule flags Windows file creation events where the target process image matches known legitimate application binaries (such as common Office apps and LOLBins) and the file is written to locations that are uncommon for normal application data handling. Attackers can abuse trusted binaries to drop or download payloads into paths like Temp, ProgramData, Perflogs, AppData, or startup-related directories to blend in with routine system activity. It relies on Windows file event telemetry containing the process Image filename and the TargetFilename path.
Reporting behind it
Changelog
v2- v2Candidate ingested via manual entry.2026-07-31
- v1No changelog recorded for this version.2026-07-30
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: "Windows File Events: Legitimate Applications Writing Executables to Uncommon Locations"
id: 326486f2-9fe3-4bfc-8bc3-395092df61ec
related:
- id: 2ddef153-167b-4e89-86b6-757a9e65dcac
type: similar
- id: 1cf465a1-2609-4c15-9b66-c32dbe4bfd67
type: derived
status: experimental
description: This rule flags Windows file creation events where the target process image matches known legitimate application binaries (such as common Office apps and LOLBins) and the file is written to locations that are uncommon for normal application data handling. Attackers can abuse trusted binaries to drop or download payloads into paths like Temp, ProgramData, Perflogs, AppData, or startup-related directories to blend in with routine system activity. It relies on Windows file event telemetry containing the process Image filename and the TargetFilename path.
references:
- https://lolbas-project.github.io/#/download
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/file/file_event/file_event_win_susp_legitimate_app_dropping_in_uncommon_location.yml
author: Swachchhanda Shrawan Poudel (Nextron Systems), Huntrule Team
date: 2025-12-10
tags:
- attack.stealth
- attack.t1218
- attack.command-and-control
- attack.t1105
logsource:
product: windows
category: file_event
detection:
selection_img:
Image|endswith:
- \eqnedt32.exe
- \wordpad.exe
- \wordview.exe
- \cmdl32.exe
- \certutil.exe
- \certoc.exe
- \CertReq.exe
- \bitsadmin.exe
- \Desktopimgdownldr.exe
- \esentutl.exe
- \expand.exe
- \extrac32.exe
- \replace.exe
- \mshta.exe
- \ftp.exe
- \Ldifde.exe
- \RdrCEF.exe
- \hh.exe
- \finger.exe
- \findstr.exe
selection_locations:
TargetFilename|contains:
- :\Perflogs
- :\ProgramData\
- :\Temp\
- :\Users\Public\
- :\Windows\
- \$Recycle.Bin\
- \AppData\Local\
- \AppData\Roaming\
- \Contacts\
- \Desktop\
- \Favorites\
- \Favourites\
- \inetpub\wwwroot\
- \Music\
- \Pictures\
- \Start Menu\Programs\Startup\
- \Users\Default\
- \Videos\
condition: all of selection_*
falsepositives:
- Unknown
level: high
regression_tests_path: regression_data/rules/windows/file/file_event/file_event_win_susp_legitimate_app_dropping_in_uncommon_location/info.yml
license: DRL-1.1