[whoknew1122]

It'll be sufficient for known malware. But if malware hasn't been identified yet, VirusTotal won't pick it up.

Is it possible that you can download malware and VirusTotal not pick it up? there's a small chance. But, in my estimation, no one is really going to burn a novel strain of malware on free ebooks. It's not targeted and that site isn't a good watering hole to deploy novel malware.

Novel strains of malware are usually reserved for specific targets. Unless you're a high profile target of an authoritarian government or known to have a high networth, I don't really think you're going to get hit with the novel stuff.

TL/DR: VirusTotal will probably be enough for the average user. But no one can guarantee safety when you're downloading random files on the internet.