The eclipse-winsigner-plugin service is signing executables with an expired certificate
Summary
In https://bugs.eclipse.org/bugs/show_bug.cgi?id=580080 it is reported that the installer executable on Windows is signed with an expired certificate. I also looked at the executables in the root of the zipped version of the installer and they too are signed with an expired certificate:
https://download.eclipse.org/oomph/products/eclipse-inst-win64.zip
E.g., it shows this:
The same build properly signs jars with the recently new certificate so I think the windows signing service is just not signing executables (*.exe and probably *.dll) with a new certificate.
Additional details are in the Bugzilla.