Windows Execution of IOX (iex/port forwarding) Tunnel/Proxy Tool via Process Creation
Alerts on Windows process creation for iox.exe with tunneling/proxy forwarding command-line parameters.
- Product
- windows
- Category
- process_creation
- Author
- Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
- Published
- 2022-10-08
- Updated
- 2026-07-30
ATT&CK techniques
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 execution of iox.exe on Windows when the command line includes port forwarding and intranet proxy parameters. Attackers may use tunneling tools to route traffic through compromised hosts and reach internal services while hiding the true origin. It relies on process creation telemetry, including the executed image path, command line arguments, and optional file hash matches to confirm the tool.
Reporting behind it
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: Windows Execution of IOX (iex/port forwarding) Tunnel/Proxy Tool via Process Creation
id: 4408c537-2e91-45d8-9c94-6c4033e16f84
status: test
description: This rule flags execution of iox.exe on Windows when the command line includes port forwarding and intranet proxy parameters. Attackers may use tunneling tools to route traffic through compromised hosts and reach internal services while hiding the true origin. It relies on process creation telemetry, including the executed image path, command line arguments, and optional file hash matches to confirm the tool.
references:
- https://github.com/EddieIvan01/iox
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_pua_iox.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2022-10-08
modified: 2024-11-23
tags:
- attack.command-and-control
- attack.t1090
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith: \iox.exe
selection_commandline:
CommandLine|contains:
- ".exe fwd -l "
- ".exe fwd -r "
- ".exe proxy -l "
- ".exe proxy -r "
selection_hashes:
Hashes|contains:
- MD5=9DB2D314DD3F704A02051EF5EA210993
- SHA1=039130337E28A6623ECF9A0A3DA7D92C5964D8DD
- SHA256=C6CF82919B809967D9D90EA73772A8AA1C1EB3BC59252D977500F64F1A0D6731
condition: 1 of selection*
falsepositives:
- Legitimate use
level: high
license: DRL-1.1
related:
- id: d7654f02-e04b-4934-9838-65c46f187ebc
type: derived