If the file size is 0KB or very small, the download was likely interrupted; you will need to re-fetch it from the original source.
Many files with this naming convention are encrypted. Check the description of the Telegram post or the pinned messages in the group where you found it for a password.
Before opening, upload the file to VirusTotal to ensure it does not contain embedded scripts or malware.
Open the PDF in a web browser (like Chrome or Firefox) rather than a desktop PDF reader to limit the file's access to your system.
Online
Sales One
Sales Two
Sales Three
Sales Four
Sales five
Office