It has higher privileges than an Administrator account to protect core system files from accidental deletion or unauthorized tampering.
This tool verifies the integrity of every system file, including TrustedInstaller.exe. If damaged, Windows automatically repairs it from its own cached copy. trustedinstaller.exe download
Fake antivirus alerts or malware often use this exact language to trick you into downloading a "fix" from a shady website. It has higher privileges than an Administrator account