cat file.txt | while read line; do echo $line | sed "s/\(\([^,]\+,\)\{9\}\)/\1$((RANDOM%1000000+8243678))/"; done
[root@node1 /]# ps aux | grep "sshd: root"
root 8039 0.0 0.1 135632 4924 ? Ss 17:00 0:00 sshd: root@pts/0
[root@node1 /]# grep 8039 /var/log/secure
Feb 5 17:00:47 node1 sshd[8039]: Accepted publickey for root from 192.168.18.41 port 33842 ssh2: DSA of:09:k6:m7:q0:qw:1q:26:01:t3:r4:6h:h6:b7:az:1w
Feb 5 17:00:47 node1 sshd[8039]: pam_unix(sshd:session): session opened for user root by (uid=0)