Native Windows Event Viewer launcher (eventvwr.exe). On affected builds, a user who is already in the local Administrators group can arrange for the auto-elevated launcher to resolve HKCU\Software\Classes\mscfile\shell\open\command to a chosen program; launching Event Viewer then starts that program at high integrity without a consent prompt. This is a UAC bypass, not elevation from a standard user to administrator. Windows 10 Insider Preview build 15007 changed eventvwr.exe to launch mmc.exe directly, so build applicability must be checked.
RESTRICTED_ACCESS_BLUR_MARKER