I just wanted to add that I'm also having the "Publisher Unknown" Issue for IntuitUpdater.exe. I followed along with @diverjer 's initial analysis and I'm seeing the same thing as of March 1st, 2024. When I start my freshly installed turbo tax it does one update with out the "User Account Control" yellow box, but then all subsequent update attempts are giving me the "Publisher Unknown" warning. My current installed TurboTax version is 2023.47.21.48. The "C:\Program Files\Common Files\Intuit\Update Service v5\IntuitUpdater.exe" does not appear to be getting updated as the date on mine is 9/15/2023 12:46AM, and the initial update ran today 3/1/2024. The version for IntuitUpdater.exe is 5.1.50.0 (according to the properties dialog).
I also grabbed the details from the "Publisher Unknown" warning but I'm uncertain if any of the tokens in there need to be kept private.
I thought I should add that I purchased Turbo Tax Delux from Amazon and used the Amazon download to install it on Windows 11 Home, Version 22H2, OS Build 22621.3155.
I helped my mother install her Turbo Tax Premium, purchased from Costco, on her Windows 11 Laptop and encountered the same "Publisher Unknown" warning for updates after the initial update. I beleive she downloaded the install package directly from Intuit.
