/usr/bin/winswitch_ssh_Xnest is in winswitch 0.12.20+dfsg-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/../lib/winswitch/winswitch_ssh_Xnest
/usr/bin/../lib/winswitch/winswitch_ssh_Xnest