The WinRAR post doesn't say that the file was submitted to VirusTotal, only that the CA said it "looked like a file used by hackers". Either there was no VirusTotal record for it or there was and WinRAR omitted that fact because it weakened their argument.
Also this file (if it existed) was used to justify a business critical decision. Why wasn’t there a paper trail for this file. Why wasn’t this data archived?