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Security: M5Devs/OpenROM

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SECURITY.md

Security & Privacy

OpenROM is a local desktop application. This document covers our security practices, privacy policy, and bundled tool transparency.

Privacy

What We Collect

Nothing. OpenROM does not collect, transmit, or store any personal data.

What Stays on Your Device

What Where Why
Application settings OS config directory Save your preferences
Conversion logs OS config directory /logs/ Debug and audit trail

OS config directory locations:

  • Windows: %APPDATA%\OpenROM\
  • macOS: ~/Library/Application Support/OpenROM/
  • Linux: ~/.config/OpenROM/

You can delete these files at any time.

Your ROM Files

  • Processed entirely on your local machine
  • Never uploaded, scanned externally, or shared
  • Temporary files are deleted automatically after each job

Network Access

OpenROM makes no network requests by default. Two optional online features exist, both disabled by default and requiring explicit user opt-in:

  • Auto-update check (GitHub releases API)
  • RetroAchievements hash lookup (retroachievements.org API) Neither feature collects personal data. No telemetry, no analytics, no cloud sync — ever.

Antivirus False Positives

Some antivirus tools may flag OpenROM's release ZIP. This is a known false positive caused by bundled emulation binaries — not actual malware.

Why It Happens

OpenROM bundles open-source tools (chdman, maxcso, ecm, xdelta3, etc.) as native executables. Antivirus heuristic engines sometimes flag:

  • ZIPs containing multiple executables (spreader heuristic)
  • Compression tools that use SIMD/AVX2 instructions (ml.score trigger)
  • Tools that launch child processes (sets-process-name heuristic)

All of these are normal behaviors for emulation and ROM tools — not indicators of malware.

Verified Detection History

Release VirusTotal Score Notes
v2.6.0 (PyInstaller) 27/67 PyInstaller heuristic
v2.6.1 (Nuitka) 14/67 Nuitka onefile heuristic
v3.5.0+ (Dart) 0-2/67 Dart native binary — near zero flags

Which Tools Are Flagged and Why

Tool Flagged By Reason
ecm.exe MaxSecure only suspicious.gen — heuristic false positive on compression tools
maxcso.exe Trapmine only ml.score — ML heuristic triggered by SIMD-heavy compression code

How to Verify Yourself

If you don't trust our binaries — don't. Verify the SHA256 checksums below, or build the tools yourself from their open-source repositories.

Bundled Tools — Transparency

Every binary bundled with OpenROM is open source, built from source, and verifiable.

Tool License Source Build
chdman GPL v2 mamedev/mame MAME official releases
maxcso ISC unknownbrackets/maxcso GitHub Actions
ecm / unecm GPL v2 alucryd/ecm-tools Built from source
extract-xiso GPL v2 XboxDev/extract-xiso GitHub Actions
nodtool MIT encounter/nod GitHub Actions
xdelta3 Apache 2.0 jmacd/xdelta GitHub Actions

Don't Trust Our Binaries?

Build them yourself:

# nodtool
cargo install --locked nodtool

# maxcso
git clone https://github.com/unknownbrackets/maxcso
cd maxcso && make

# xdelta3
git clone https://github.com/jmacd/xdelta
cd xdelta/xdelta3 && ./configure && make

# chdman — part of MAME build
# https://github.com/mamedev/mame

SHA256 Checksums

Verify the bundled binaries against these checksums before running OpenROM.

Windows

972cad9fc243ba8d393cd9bfe566af0740e9df543b628b076b99fe77b8d24d20  chdman.exe
d49e12f3ebb6d75ed59d95368ed323f7ab2b0f5351e42fd7417ff43593cacb81  ecm.exe
7c7af9c17e095c3c1e78e644df5f0e72f01c4690b3117f038aafe26eb5a8a2f4  extract-xiso.exe
05f90b74c4ccdb48f93f9e4c51cc96eb959fd7596d79ba80cf6d8008495fadfb  maxcso.exe
139ec57bea9b184497a19190c44414508c9aca45b99f29d9086cf084f95288d1  nodtool.exe
45f597a50d868f2fce11877f52983b2097cf6b9ac569c35122cc3fdc28d03705  unecm.exe
53d90226615f217d3380c39892833311b4e24acd863e1ca01f14b5e772e2e6d0  xdelta3.exe

Verify on Windows (PowerShell):

Get-FileHash .\assets\windows\chdman.exe -Algorithm SHA256

Linux

88c4a766745d6610da26a2c9c34919336d82e073c165e5fffed620a464fddb4c  chdman
bb1bb971985fed6a8d92a2e8bebd6a41cfaa775879b462636dd25c78fba06b42  ecm
5d3405746601b723a67fdd5db06e6c225943a9513001f6e80643373f3ed3e947  extract-xiso
1e4a395b104ed4ffe8127bcf665e98738b5061bc6548552c5338552f14699ba3  maxcso
690c8de88589b8831b8d0064eb98048ad86610b77f4ef2ece41e370b1a6c6d2e  nodtool
5b5f1077fcd0fdbd105a5edc95c3e580ab4291242936a40677554e8458fdc5af  unecm
0d38d86de5ab6bbc1adae531331d64585b5a09ce3604a5f090c27f71b6a64b23  xdelta3

Verify on Linux:

sha256sum assets/linux/chdman

macOS (Apple Silicon — arm64)

375a31e0fe0b3bc55dbc03cadd29ddc698a5f0fc8b03bb1aff658b1a3c74fede  chdman
8eb577701167b22a4bd8226475a653a831d01e9aa4204e3d6468acea3e8bb3e5  ecm
a46e8f9e0384e47b8a933a8709124c93a0aefe46105adb4678c5e7f9902afcc4  extract-xiso
1b3bf24ee995f7313b5ba9d89afcd40e69bdf331020f42635ad1996a2c9b9e3e  maxcso
206f78c3598fe66d277fbace86f9cb7e163f92a9e5881df2354aced452b7ce91  nodtool
99eafff431f343f352a24cf5dafe5ef43c8b67178e0f4249b3fdcdaf2067ed4b  unecm
244a2643774155ab7dc563258a203674feafbbddc7f1f4a4f4486b00e78c1941  xdelta3

macOS (Intel — x86_64)

b0e143f52ce4ad0505a859914154efee13900609d047e9d885bf0ed552892c16  chdman
114079a1b564d487adea99d0c30f505709158f10f7033dd0d765c1f7fc16784e  ecm
a46e8f9e0384e47b8a933a8709124c93a0aefe46105adb4678c5e7f9902afcc4  extract-xiso
5e61a500d54e565cb88266d2346cdb9cc864e15316a59933872cee5ffc3dbd0d  maxcso
4603f0171fda5f4beae794dec84d423e3bb5309c34f5af9842d38ab2507d2bb6  nodtool
06b1e0fe9574a140f7b7aab70155e3415e631c90be3184b33f396cdb9a2cf113  unecm
244a2643774155ab7dc563258a203674feafbbddc7f1f4a4f4486b00e78c1941  xdelta3

Verify on macOS:

shasum -a 256 assets/macos/arm64/chdman

Reporting a Vulnerability

If you discover a security vulnerability in OpenROM:

  1. Do not open a public GitHub issue
  2. Use GitHub Security Advisories (private & encrypted): 👉 github.com/M5Devs/OpenROM/security/advisories/new

We aim to respond within 72 hours and release a fix as soon as possible.

Third-Party Tools — Licenses

OpenROM bundles third-party tools. Their licenses are installed alongside the app:

$INSTALL_DIR/licenses/

Each tool's license is also available at its source repository linked above.

Last updated: 2026-10-05 M5 Dev — github.com/M5Devs/OpenROM

There aren't any published security advisories