So far the only response I have had is a pretty stock one (and I'm sure that 'Don' this is an automated email system, not a real person!)
Thank you for writing to iTunes Store Support. My name is Don, and I'll be looking into your concern today
I understand that your Anti-Virus program is detecting a trojan when you download an update for the application "QuickPlan". I can certainly comprehend the seriousness of this matter. Let me see what I can do to help.
Apple takes the quality of products offered on the iTunes Store very seriously, and will investigate the issue you reported in-depth as well as the vendor being notified. I can't say when or if the vendor will correct the issue.
Ian, I suggest that you report this to the developer (Hao Li) as well. This will ensure that proper actions are carried out as quickly as possible. You can visit their support site at:
Thank you for your patience as we work to make your experience with the iTunes Store more enjoyable.
In the meantime, you may wish to look for other applications brought to you by the iTunes Store.
Please accept my apologies for any inconvenience this has caused. Your patience and understanding are greatly appreciated.
I wish you all the best and I hope that you continue to enjoy purchasing at the iTunes Store.
I did early on contact Hao Li and was told that they would contact Avast to straighten out this false positive.
And yet.... I wish I understood what was going on with this apparent effort to download a Windows executable via an iOS app update to begin with, even before the warning that that executable was infected.
Given the amount of advertent and inadvertent malware out there, more and more of it in state-sponsored industrial espionage, and given the evidence so far, a great deal of extra caution is warranted, IMHO.