Many legitimate third-party retailers sell "OEM keys" or "Grey Market keys" for a fraction of the retail price (often under $20). While these exist in a legal "grey area," they allow you to use the official installer from Microsoft, which is much safer than a pre-activated file.
MS Office Pre-Activated: Everything You Need to Know Before Downloading ms office pre activated
You don't have to risk your data to use Office. There are several legitimate ways to get the suite for free or at a massive discount. Many legitimate third-party retailers sell "OEM keys" or