Alternatively, the user may be looking for a (e.g., from Microsoft’s own download site) with a new product key. However, Microsoft does not distribute Office 2016 ISOs with "ptbr" explicitly labeled that way for consumers. Official ISOs are behind VLSC (Volume Licensing Service Center) or TechBench, and they are not called "new." So, piracy is the near-certain intent.
Many websites exploit this exact keyword to lure unsuspecting users. Here is what you risk by downloading from unverified sources: microsoft office 2016 ptbriso new