(Microsoft) Debugging Tools for Windows (x64) -- this is part of the Windows SDK 7.1 package, available via web installer or full ISO image. Probably affects other installers in the SDK, since they were most likely built with the same authoring tools. If downloading the ISO, the full path in the image is \Setup\WinSDKDebuggingTools_amd64\dbg_amd64.msi. The internal package version is reported to be 22.214.171.1243.
I did not want to install the entire SDK; I only needed the Debugging Tools package. However, due to a problem with web installer, I ended up downloading the ISO and extracting the MSI package for just the x64 Debugging Tools. If it would help, I can provide a copy of the package if you can provide a place for me to upload it.
At the beginning of the installation process, Unchecky prevents me from agreeing to the EULA for the Debugging Tools. After I closed and restarted the installation the third time, Unchecky did not throw a false positive. This may be because I renamed the file from dbg_amd64.msi to Debugging Tools for Windows x64.msi. I don't have time to test further just now.
Let me know if I can provide additional information. If you experience problems downloading and testing just the Debugging Tools package, again, let me know, and I can provide a copy of just that package.
Customer support service by UserEcho