Download Source Verification
According to the questions and the good answers on the right. If the website fulfils these points it's safe to assume the website is correct and authentic.
If all question can be answered with "Yes" the download is verified to be secure enough. Always keep in mind, if something on the page or download gives you a second guess, second guess it!
Official Site: Software safe to use
Unofficial Site, do NOT use this Software
Software Verification: Found in "properties"
These information can be checked in the "Properties" of each file.
Simply by checking the meta information of the software, most if not all concerns about a software can be eradicated easily. Keep in mind to check the hashes as well as the software version. If a software of a vendor does not own a signature nor normal meta data, discard the software at all costs.
If you're insecure regarding the software, always ask for help or reassurance