Воспользоваться VB макросом:
Sub Password_Cracker()
Dim i As Integer, j As Integer, k As Integer
Dim l As Integer, m As Integer, n As Integer
Dim i1 As Integer, i2 As Integer, i3 As Integer
Dim i4 As Integer, i5 As Integer, i6 As Integer
Dim password As String
On Error Resume Next
For i = 65 To 66: For j = 65 To 66: For k = 65 To 66
For l = 65 To 66: For m = 65 To 66: For i1 = 65 To 66
For i2 = 65 To 66: For i3 = 65 To 66: For i4 = 65 To 66
For i5 = 65 To 66: For i6 = 65 To 66
password = Chr(i) & Chr(j) & Chr(k) & Chr(l) & Chr(m) & Chr(i1) & Chr(i2) & Chr(i3) & Chr(i4) & Chr(i5) & Chr(i6)
For n = 32 To 126
password = password & Chr(n)
ActiveSheet.Unprotect password
If ActiveSheet.ProtectContents = False Then
MsgBox "Password cracked"
Exit Sub
End If
Next: Next: Next: Next: Next: Next
Next: Next: Next: Next: Next: Next
End Sub