: Run the file through VirusTotal to ensure it doesn't contain malware.

: Use VLC Media Player if the files are videos or audio.

RAR is a compressed format that requires specific software to "unpack" or extract.

: Use 7-Zip or WinRAR . Right-click the file and select Extract Here . Mac Users : Use The Unarchiver from the Mac App Store. Mobile Users : Use the RAR app for Android or iZip for iOS. Important Safety Checklist Before opening a file with an cryptic numeric name:

: Use Microsoft Office or Google Docs for .docx or .xlsx files.