We might need pccntmon to help us get user account information.

Action Plan:
Privileges and Other Settings -> Other Settings -> Security Agent Access Restriction ->
[ ] Do not allow users to access the Security Agent console from the system tray or Windows Start menu

Make sure you can see pccntmon and then try again.

After reload agent or re-login by different user, you should be able to see logon user information here:

[HKEY_LOCAL_MACHINE\SOFTWARE\TrendMicro\PC-cillinNTCorp\CurrentVersion\Misc.]
"LogonUserAccount"="MOC-TEST\\Usuario nuevo"
"LogonUserDistinguishedName"=""
"LogonUserGUID"=""
"LogonUserPrimaryGroupID"=""
"LogonUserSID"=""
"LogonUserPrincipalName"=""
"LogonUserCachedDCPolicyGUIDIn"="E07D950A-EB06-42BA-885B-B077B3727E43:a36b40d7-857d-a4d5-7245-3647e98e2659:1"
"LogonUserCachedDCPolicyGUIDOut"="E07D950A-EB06-42BA-885B-B077B3727E43:bde9f348-ee21-7ce2-d426-416a5871423c:1"