Prevent copying of Excel files

I want to prevent users in my enterprise from copying certain Excel files or if they do, I want to know if they have (possibly through some compare method if I have a guid or something in a database of all original excel files). Thanks!

Solution 1:

If the users have direct access to the excel files from within the OS / hard drive / network drive you will have an impossible time trying to prevent copying. More so if they need read and write access or admin privileges on the computer.

You could try moving the data to an online platform such as Google Sheets, Excel for the Web or another online database. In e.g. Google Sheets you can prevent shared users to make copies, download, print or re-share, but probably not prevent copy-pasting the raw data out (e.g. client email addresses pasted into notepad).

If the above is not possible, you should at least password protect the file. This would prevent access to the data by unauthorised parties. Obviously authorised users (with knowledge of the password) could still copy the file and steal the data (e.g. a disgruntled employee). To prevent this, you could possibly add VBA macro code to the Excel file with your own data obfuscation and user authentication methods that will verify a users credentials against some server's. If an employee/user leaves, you can revoke their credentials. This would deter casual data theft, but a determined user could still copy and paste data out, save a macro free copy or export to csv. You could also add code to ping a listening server every time the file is opened.

For very sensitive data, you could look into running a sort-of spyware program on all company computers. You can plant fake & unique entries into the data and have the spyware program scan all actively saved files for these fake data entries. You could also lock down USB ports, block attachments on emails and block/filter internet access. This is an advanced solution, probably requiring custom development and special OS policies and rules for any anti-virus software.

My last 2 cents, almost all companies have sensitive or private data. At some point you have to trust your employees and rely on your ICT policies and employment conditions to protect your data or at least make employees responsible and liable for data leakages. New privacy laws in most countries will in many cases make this a criminal offense too.