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: