You would know better than I. However, I assume that it's not just attached to the file itself, as it got attached to a bunch of them.
I can only imagine what might be possible, but I've been Microsoft-free since Word 4.0 (which I liked btw), since I switched to ClarisWorks somewhere in the early 90s.
However, no matter what the answer, I don't think Excel (or any other software) should be able to go back and change files in Time Machine. That entirely defeats the purpose of having such a backup.
Isn't that a design issue for Apple to be concerned about?
Apple should prevent you from giving your admin password to Microsoft (installer) software?
You may be right but it would never have been a saga, or any kind of a thread, if I could have relied on a Time Machine copy of the file. Then I would simply have replaced the file with one that did not have password protection.
I think it's a serious problem if any software can modify backups without the permission of the drive administrator.
I don't know if it's been proven that older backups were modified. It's possible that Excel is retroactively protecting older files based on some lookup table (i.e., based on either name or some document ID it could "decide" to start protecting older versions, if enough criteria match. (not saying that's what happened, just that it's not impossible).
Again, as to the older versions in Time Machine's backup, the only thing that could protect them is your admin password... and installers can either store that text or construct some sort of root-helper app at install time.
I don't know whose fault this is, but (so far) Apple's name seems last on the list.
