How does VBA Protection work?

An honest explanation of what this service protects — and how far.

1. Why it matters

Excel macro (VBA) code can be opened by anyone in the editor by default, exposing the logic and formulas you worked hard to build. Even if you set the VBA editor's "project lock" password, tools that bypass it are widely available online and defeat it fairly easily.

VBA Protection keeps your macro code from being easily exposed, even by such bypass tools.

2. Two layers of defense

① Hide, block, and confuse

Editor lock — the protected file's project is locked in the Excel VBA editor, so the code is not shown.
Bypass-tool noise — large amounts of decoy values are planted in the lock information that automated bypass tools target, so ordinary users and most automated tools cannot open the code.
Code info removed — code information inside the Excel file is invalidated, making decompilation attacks difficult.

Even though the code is hidden, the macros still run normally. The code remains in the file — it is simply made invisible to the user.

② Obfuscation — the last safety net

Excel only "encodes" VBA code rather than "encrypting" it, so extraction of the source with a dedicated tool cannot be blocked 100%. VBA Protection therefore stores the source itself in an obfuscated form. Even if layer ① is breached and the code is extracted, restoring the original, intact source is difficult and its meaning is hard to grasp.

Below is an example of obfuscated code.

Option Explicit
Sub RenameFilenames()
Dim I As String
Dim l As Object
Dim II As Object
Dim Il As Long
I = ActiveSheet.Cells(1, 1).Value
Set l = CreateObject((ChrW(&H53) & ChrW(&H63) & ChrW(&H72) & ChrW(&H69) & ChrW(&H70) & ChrW(&H74) & ChrW(&H69) & ChrW(&H6E) & ChrW(&H67) & ChrW(&H2E) & ChrW(&H46) & ChrW(&H69) & ChrW(&H6C) & ChrW(&H65) & ChrW(&H53) & ChrW(&H79) & ChrW(&H73) & ChrW(&H74) & ChrW(&H65) & ChrW(&H6D) & ChrW(&H4F) & ChrW(&H62) & ChrW(&H6A) & ChrW(&H65) & ChrW(&H63) & ChrW(&H74)))
If Not l.FolderExists(I) Then
Exit Sub
End If
Set II = l.GetFolder(I)
Il = 1
Call RenameFilesInFolder(II, l, Il)
End Sub

3. Limitations (told honestly)

A file protected by VBA Protection is not easily broken by ordinary users or automated bypass tools. However, since the source remains in the file (in obfuscated form), a skilled attacker's manual analysis may expose the obfuscated source.

This service therefore aims to ▲block easy code viewing by ordinary users and automated tools, and ▲ensure that, in the worst case, only obfuscated code — not the intact original — remains.

4. Supported files

Macro-enabled .xlsm / .xlam / .xlsb files
Please remove the workbook (file) password before uploading. The VBA "project properties" password may stay on.
Excel versions: works on most versions that support VBA, though not all have been tested. If something doesn't work, let us know → vbaprotect.contact@gmail.com
File size: only files 25MB or smaller are processed, due to server capacity.

5. Please note

During protection, the original comments and line breaks are removed and the code is obfuscated. We have verified correct behavior with many files, but please always confirm that the protected file works correctly, and keep a separate backup of the original file before converting.

This is not a commercial service and is provided as-is. The decision to use it, and verifying and using the converted file, are entirely the user's responsibility. The operator makes no warranty and is not liable for any damages arising from use of this service. Ownership of the converted file belongs to the user; this site claims no rights to it. (This is a beta service and may change or stop without notice.)

6. Privacy

Uploaded files are not stored on the server. They are converted in memory, returned to the user immediately, and vanish from memory right away — so no information about the file remains on the server.
The service is used without login, so no user information is kept on the server either.

7. Note

This service is built with Rust.

← Go protect a file