VTCheck

A "Check on VirusTotal" entry in the Windows Explorer right-click menu. Right-click a file → it's checked via VirusTotal → a verdict (CLEAN / DANGEROUS / SUSPICIOUS / UNKNOWN) shown in a console window.

Install

1. Download VTCheck-Setup.exe from Releases.
2. Run it and install. No administrator rights needed — everything is installed into the current user's own folder.

Requirements

• Windows 11 (should also work on Windows 10).
• Your own free VirusTotal API key — https://www.virustotal.com/gui/my-apikey. The key is entered on first use and stored encrypted (DPAPI) in %APPDATA%\VTCheck\config.json, tied to your Windows account.
• curl.exe (built into Windows 10/11) — only needed to upload files VirusTotal hasn't seen yet; checking already-known files works without it.

The free VirusTotal key is limited to 4 requests per minute and 500 per day.

Building from source (for developers)

The ready-made installer is on the Releases page. The steps below are for building it yourself or changing the code.

1. Install NSIS (makensis), PowerShell 7 (pwsh), and the Pester test module.
2. Bump VERSION if needed.
3. Run build.sh (Linux/macOS/WSL), or the equivalent steps by hand on Windows: Invoke-Pester -Path tests -CI, then makensis installer.nsi.

The build runs the test suite first (tests/, 88 tests) and fails if any test fails or the run doesn't happen at all.

Constraints that matter for contributors

• Target version is PowerShell 5.1 (the built-in powershell.exe — that's what the menu entry actually launches) — no PowerShell 6+ syntax.
• All .ps1 files and installer.nsi are UTF-8 with BOM; without it PowerShell 5.1 reads non-ASCII text as garbage.
• Any path that comes from the user gets -LiteralPath, never -Path.
• Registry writes are HKCU only — no administrator rights required.

How it's built

• src/scan.ps1 — entry point (receives %1 from the menu item).
• src/logic.ps1 — verdict logic and upload strategy.
• src/api.ps1 — VirusTotal requests (TLS 1.2; path and key go to curl through a temporary --config file, not through process argv).
• src/ui.ps1 — console screens.
• src/config.ps1 — key storage.
• installer.nsi — NSIS installer: menu entry, launch command, entry in the installed-programs list — all under HKCU.

License

MIT — see LICENSE.