: Before opening the file, upload the download link or the file itself to a service like VirusTotal to check it against dozens of antivirus engines.
: Look at the domain name where the download is hosted. Authentic services (e.g., ://google.com , dropbox.com ) are generally safer than strings of random letters or suspicious top-level domains (like .xyz or .top ). Download File ac4xx4nklnnm.pdf
Could you clarify or what specific functionality you are trying to build for it? : Before opening the file, upload the download