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WinMasterBlocker

WinMasterBlocker — block Adobe, Autodesk and Corel from the internet using Windows Firewall

Download latest MIT License GitHub stars CI status Last commit Windows 10 22H2 / Windows 11 No dependencies

Windows 10 support tracks Microsoft's consumer ESU window and will be reduced to best-effort after October 13, 2026.

A small Windows batch script that uses the built-in Windows Firewall to block Adobe, Autodesk, Corel, Maxon and Red Giant applications from reaching the internet. No drivers, no kernel hooks, no third-party services, no subscription. The script reads a vendor list, walks every install directory it knows about, and adds inbound and outbound block rules per executable through netsh advfirewall.

If you have ever watched acrocef.exe, RdrCEF.exe or the Adobe Genuine Service phone home minutes after a fresh install, this is for you.

What it blocks

Vendor Why you might want this Common process names blocked
Adobe License-server polling, telemetry, Creative Cloud sync, Acrobat CEF children acrocef.exe, RdrCEF.exe, Acrobat.exe, AcroRd32.exe, AdobeNotificationClient.exe, AdobeIPCBroker.exe, Creative Cloud.exe
Autodesk Single-sign-on heartbeats, AutoCAD telemetry, license-manager polling every *.exe under Autodesk\ and Autodesk Shared\
Corel Activation server checks, update prompts every *.exe under Corel\
Maxon Cinema 4D license polling, render-node check-ins every *.exe under Maxon\
Red Giant Trapcode license heartbeat, Universe activation every *.exe under Red Giant\

Coverage is two-layered. First a recursive walk of every known install path (%ProgramFiles%\Adobe, %LOCALAPPDATA%\Adobe, %APPDATA%\Adobe and the rest). Then a vendor-specific known-process sweep that scans every other logical drive's \Adobe\ root and %USERPROFILE%\Adobe\ for the specific binaries that have historically slipped past — covers custom installs to D:\Adobe\ or any other non-default drive the main walk cannot reach.

Quickstart

  1. Download WinMasterBlocker.bat from the latest release. Verify with certutil -hashfile WinMasterBlocker.bat SHA256 against the SHA256SUMS.txt from the same release.
  2. Right-click it, Run as administrator. If you double-click, the script re-launches itself with elevation through PowerShell.
  3. Pick a vendor from the menu. Pick 98 after a vendor update to re-scan and add any new executables. Pick 99 to remove every rule the script added.

A transcript log lands at %TEMP%\WinMasterBlocker-YYYYMMDDhhmmss.log. Every check, skip and rule add is recorded there. Most "it did not work" reports are answered by reading the last 50 lines of that file.

How it compares

WinMasterBlocker SimpleWall NetLimiter GlassWire
License MIT LGPL Commercial Commercial
Price Free Free $30 / 2 yr $39 / yr
Third-party driver None WFP filter driver WFP filter driver WFP filter driver
Per-application rules Yes (per .exe) Yes Yes Yes
GUI None (menu only) Yes Yes Yes
Profile-aware (Domain / Private / Public) No (rule applies to all) Yes Yes Yes
Scriptable / unattended Yes (env vars) Limited Yes No
Auditable in plain text Yes (17 KB single file) No No No
Survives reboot Yes (Windows Firewall persists) Yes Yes Yes
Survives uninstall of the tool Yes (rules are native) No No No

WinMasterBlocker is for the case where you want firewall rules and only firewall rules: visible in wf.msc, exportable through netsh advfirewall export, removable through Group Policy, the same shape an enterprise admin would write by hand. If you want a packet log, an outbound prompt UI or per-NIC bandwidth shaping, use one of the commercial tools above.

FAQ

Is this safe to run?

Yes. The script only invokes net session, netsh advfirewall firewall add rule, netsh advfirewall firewall delete rule, and a single PowerShell call to enumerate existing rules. No registry edits, no service installs, no driver loads, no scheduled tasks. Every action is written to the transcript log before it is executed, and every change is reversible from the Windows Firewall UI (wf.msc) or by running this script with menu option 99. The full source is one batch file, around 450 lines, that you can read top to bottom in five minutes. There is no telemetry, no auto-update, and no network call from the script itself.

Will Adobe still activate after I run this?

Yes, with one caveat. Adobe activation reaches the network through Adobe Desktop Service.exe and node.exe under Creative Cloud, both of which the recursive walk will block. Run the script first, complete activation while temporarily disabling the relevant rules, then re-enable them. The simpler path for most users: install and activate first, then run WinMasterBlocker. Subsequent re-activations after license changes will need the same temporary unblock.

Why is acrocef.exe still connecting after I ran the script?

Three causes account for almost every report. First, Acrobat was installed or updated after the last run; re-run the script, or pick option 98 (Update Adobe). Second, Adobe placed a new CEF child under %LOCALAPPDATA%\Adobe\ that the previous version of WinMasterBlocker did not walk; this version walks both %LOCALAPPDATA% and %APPDATA%. Third, the previous version made a slow PowerShell duplicate-check call per executable and large Adobe installs took five minutes or more to finish; users killed the run before AcroCEF was reached. The 2.0 release replaces that with a single up-front rule cache, so the Adobe walk completes in seconds.

How do I undo a block?

Run WinMasterBlocker.bat and choose option 99 from the menu. You then pick whether to delete inbound rules, outbound rules, or both. The script only removes rules whose display name ends in -block, which is the suffix it appends to every rule it creates, so it will not touch firewall rules added by other tools or by Windows itself. You can also remove rules from the GUI (wf.msc, sort by Name, find rules ending in -block) or with netsh advfirewall firewall delete rule name=all dir=out if you want a fresh start across every outbound rule on the machine.

Does the block survive Adobe updates?

The rules survive. New executables introduced by an update do not get blocked automatically, because the rules target specific paths. After an Adobe Acrobat or Creative Cloud update, run the script again and pick option 98 (Update Adobe). The cache-aware duplicate detection means existing rules are skipped instantly; only new executables get new rules. The transcript log lists every rule added on that pass, which makes it easy to confirm that the new CEF children from the update are now blocked.

Will it block Windows Update or Microsoft Defender?

No. The vendor list contains Adobe, Corel, Autodesk, Maxon and Red Giant only. The recursive walks happen under %ProgramFiles%\<vendor>\, %ProgramFiles(x86)%\<vendor>\, %CommonProgramFiles%\<vendor>\, %ProgramData%\<vendor>\, %LOCALAPPDATA%\<vendor>\ and %APPDATA%\<vendor>\. Nothing under %WINDIR%, %SystemRoot%, %ProgramFiles%\WindowsApps or %ProgramFiles%\Windows Defender is touched. If a vendor binary is somehow installed inside one of those locations, the script will walk it; that is rare and would be a packaging mistake worth a separate report.

Troubleshooting

The transcript log at %TEMP%\WinMasterBlocker-YYYYMMDDhhmmss.log records every action. If the script "did nothing", open the latest log: it will show either path missing for every Adobe path (you do not have Adobe installed where the script expected, or the elevation switched user contexts and lost %LOCALAPPDATA%), or skip "<rulename>" for every executable (the rules already exist from a previous run), or a list of add lines (it worked, the rules are now in wf.msc).

Set WHATIF=1 in the environment before running to see what the script would do without making any firewall changes. Useful as a dry run after editing the script or paths.

For IT pros and unattended use

Four environment variables drive an unattended run from a deployment script, MDM payload or scheduled task:

set WHATIF=1
set WMB_VENDOR=Adobe
set WMB_ACTION=block
set WMB_QUIET=1
WinMasterBlocker.bat

WHATIF=1 logs every netsh call without executing it (dry run). WMB_ACTION=delete removes every rule added by the script. WMB_QUIET=1 suppresses per-rule console output (the transcript log is still written). All four survive the UAC re-launch when the script elevates itself on double-click.

To export the resulting rules into a .wfw file you can re-import on other machines, or push through Group Policy:

netsh advfirewall export "C:\share\winmasterblocker-rules.wfw"

The exported file is a binary blob that netsh advfirewall import understands on any Windows 10 or 11 host.

Contributing

Contributions for new vendors and new install paths are welcome.

git clone https://github.com/ph33nx/WinMasterBlocker
cd WinMasterBlocker
# Install lefthook (https://lefthook.dev), then:
lefthook install

The pre-commit hook runs tools/lint-bat.sh, tools/format-check.sh and tools/audit-coverage.sh against WinMasterBlocker.bat. The audit script asserts that the Adobe known-CEF list still contains acrocef.exe, RdrCEF.exe and the other binaries that earlier issues identified, so the regression that originally inspired #6 cannot silently come back.

A new vendor:

set "vendors[5]=NewVendor"
set "paths[5]=%ProgramFiles%\NewVendor;%ProgramFiles(x86)%\NewVendor;%LOCALAPPDATA%\NewVendor"

A new known-bad executable for an existing vendor: append it to the relevant for %%E in (...) list in the :adobe_sweep_root helper (or the equivalent for other vendors as they grow) and add it to REQUIRED_ADOBE_EXES in tools/audit-coverage.sh so future commits cannot drop it.

Citation

A CITATION.cff is included; GitHub renders a "Cite this repository" button on the right sidebar. If you reference this tool in articles or research, please cite the repository directly rather than copy-pasting the script.

License

MIT. See LICENSE. SPDX identifier MIT is set in the script header.

Author

@ph33nx