VirusTotal - Multi-engine online virus scanning service

VirusTotal is an online virus scanning website that uses more than 30 domestic and international antivirus engines to scan files uploaded by users, determining whether the files are infected by viruses, worms, Trojans, and various types of malicious software.

Users can upload files for inspection in three ways: direct online upload, email attachment sending, or uploading via a standalone client. VirusTotal will scan and analyze the file, ultimately providing a virus detection report for the user's reference. Note that it is just for reference because different security software may define viruses differently, and no single engine can provide a 100% detection rate for viruses and malware.