No single anti-malware engine is perfect 100% of the time. Using multiple engines to scan for threats allows you to take advantage of the strengths of each individual engine and to guarantee the earliest possible detection.
Total Scan not only tells you whether a given antivirus solution detected a submitted file. (Most of them will discriminate malware sites, phishing sites, suspicious sites, etc.)
The malware signatures of antivirus solutions present in Total Scan are periodically updated as they are developed and distributed by the antivirus companies. This makes sure that the products are using the latest signature sets.
File and URL scanning can be automated with a free public API. Should a user require a higher request rate, a honeypot API is available for researchers and a private mass API is offered to individuals with commercial and product enhancement intentions.
No single anti-malware engine is perfect 100% of the time. Included anti-malware vendors.
Malware Scan + Website AntiVirus