Q:

I am having difficulties with back-reference in awk

Recently, I am into security logs and want to make it better way on bash
.
I have a log file like this:
[root@localhost ~]# cat /var/log/secure
Aug  1 12:00:00 localhost sshd[1311]: Accepted password for root from 127.0.0.1 port 50000 ssh2
Aug  1 12