We found ‘rwin.exe’ is created under C$ of the target server when password changing by ‘Windows Remote’.
But it is not always created, sometimes there is no rwin.exe though eventually the password change is done correctly.
Why rwin.exe is not always created?
How the password change happens even when rwin.exe is not placed?
At first, it tries with samba commands such as smbpasswd or net.
If those fails, rwin.exe is copied to \\HOSTNAME\C$ onto the target machine and tries to synchronize the password.
These communications are done via SMB port(445) as documented in the Prerequisites for Using the Windows Remote Connector section of the Add a Windows Remote Target Connector documentation page.