Password protected Excel files cannot be opened with Malwarebytes active.

[Ready912]

I think there might be a FP with encrypted Excel files with today or last night's update.

Starting today I was unable to open any of my password protected Excel files that I use daily, including my backups downloaded from the internet or other external drives.  However I am able to open them on OneDrive and Google Drive without issue.

When attempting to open the file an error in Excel pops up saying there is a problem with some of the content in the file and asks to attempt repair.  After clicking Yes, it says the file was unrepeatable and corrupt.

 

 

Excel files without a password can be opened without any issue.

After spending an hour with Microsoft office support, the representative temporarily turned off Malwarebytes and everything was back to normal.  I could then open files that are password protected. 

The rep said that MB was stopping the files from being opened and detecting encrypted Excel files as malware.

 

I then created two brand new files one password protected and one without, to test with MB on.  Issue reappeared.

"PasswordTest" is the password for the test Excel file attached.

 

I'm on MB 4.5.9.198, update package 1.0.56033. Component package 1.0.1699;

Office 365 version 2205 build 15225.20204

Windows 10 Home
Version    21H1; OS build  19043.1706;   Experience Pack 120.2212.4170.0

Thanks!

 

fpreport-excel.txt FP-Excel.rar

[Ready912]

Issue has been resolved.

I tried cleaning the installation as suggested in the other forum, but issue didn't go away until I also disabled the Excel Macro 4.0 abuse prevention which is on by default in MB.  Restarted Windows, then issue went away.

 

 

 

[cli]

Thanks for reporting. I'm glad you were able to resolve the issue.