: Use a tool like 7-Zip or WinRAR to "Open Archive" (rather than "Extract") to see the file extensions inside. Be wary of .exe , .scr , .vbs , or .js files disguised as documents.

: Upload the file to VirusTotal to check it against over 70 different antivirus engines.

: Only open archives from trusted senders. .rar files are frequently used to package malware because they can bypass some basic email filters.