/usr/bin/who@ is in ucspi-tcp-ipv6 1:0.88-3.1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 | #!/bin/sh
# WARNING: This file was auto-generated. Do not edit!
/usr/bin/tcpclient -RHl0 -- "${1-0}" 11 sh -c 'exec /usr/bin/delcr <&6' | cat -v
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