The following message was reported by my anti-virus program TrendMicro Titanium Maximum Security:
Threat: HEU_AEGISCS929
Source: Threat
Affected Files: C:\Users\krisburg\AppDat…stall-x64-a0005-30000.exe
Response: Removed
Detected By: Real Time Scan
with the most recent program update installed today.
It's a false positive, via a heuristic detection.
TrendMicro has them a lot.
You could report the problem to TrendMicro to get them to improve their detection, although people have been reporting similar problems to them for years (not just involving Opus installers) and they still keep doing this.
VirusTotal lets you upload a file and see the results for lots of different virus checkers, which is helpful if you want to find out how likely a detection is to be a real virus rather than a false positive from poor detection algorithms. VT have recently increased their max file size, allowing the x64 installers to be scanned again, too.
VirusTotal results for the 32-bit and 64-bit English installers show no hits (even for TrendMicro with today's signatures, at least as VT has it configured):