Add domain user to ORA_DBA group

Right after Oracle 12c installation and database creation I was able to connect to the database with username and password

sqlplus sys/pass as sysdba
Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

but unable to connect with / as sysdba

sqlplus / as sysdba
ERROR:
ORA-01017: invalid username/password; logon denied

Connection from local administrator account worked perfectly without user name and password, so I’ve checked ORA_DBA group with lusrmgr.msc console and found that I have to add currently connected domain user to ORA_DBA group.
But Add user dialog doesn’t allow search and add domain users. Solution for this is command line under Local Administrator account

net localgroup ORA_DBA /add domain\USERNAME