Hello! It seems like you are looking for a safe and free software. One popular free software for working with PDF files is Adobe Acrobat Reader DC. It is the free version of Adobe Acrobat, which allows you to view, print, and annotate PDF files.
You can download Adobe Acrobat Reader DC directly from the Adobe website to ensure you are getting the legitimate and safe version of the software. Just go to the Adobe Acrobat Reader DC download page, select your operating system, and follow the instructions to install the software on your computer.
Remember to always download software from official sources to avoid any security risks associated with downloading from unknown or untrustworthy sources. Let me know if you need further assistance or have any other questions!