Malcolm, I have no toubt that you and your team didn’t add intentionally any addware. But we know that it’s enough one developer PC infected to finaly disseminate a virus. The art of a good virus is to stay unvisible as long as possible, even for expert…
May I suggest you, to investigate (using also AVG) because you have a view on all files concerned by the install program. In my place, I only see a big exe file without access to individual files. So I cannot find which file is suspected by AVG.
To share my own investigation.
On my second computer, build 31740 had been installed few weeks ago. At this time AVG didn’t detect anything.
But yesterday, it warns me on this virus.
I launched AVG to control the whole “C:\Program Files (x86)\Derivative” folder where was installed TouchDesigner. No virus detected.