Need to protect your VBA macro ? Simply damage the file !

October 8th, 2009 by Andrey Malyshev

One of our customers sent me two Excel XLA add-ins. When I tried to open that file in the VBA Editor — the "Project is locked" message appeared. Add-in has been already unlocked by our VBA password recovery tool. According to Microsoft article this message may appear in two cases: when the macro is protected by password or when it is digitally signed. I analysed the macro password record and found that the password is empty. MS Excel also showed me that macro have no any digital signatures. Then I looked into protection record with more attention and for example found that:

"[Host Extender Info]" string is replaced to "[Host Extender 1nfo]".

There were some additional similar changes and finally I found that the macro has damaged digital signature record. It’s ignored when macro is running but when we try to open the macro to view — Excel shows the error.

Microsoft has very weak VBA macro protection. That’s why developers are searching for non-standard protection methods. It’s not simple to reconstruct a damaged macro and it may require a lot of time.

If your macro cannot be opened by our password recovery programs — the most probable reason is custom protection that damages some technical records. I cannot say that it’s a good protection. New versions of MS Office may not work correctly with damaged files.


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One Response to “Need to protect your VBA macro ? Simply damage the file !”

  1. Khizar says:

    One of my file is macro protected(password forgot) and not even able to view the coding window so not even able to cract the password. So can someone let me know how it can be opened without using password. (All the options in the Visual Basic Editor window is locked)

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