SSH-2.0-OpenSSH_5.3

# cp /usr/sbin/sshd /tmp

# cd /tmp
# strings -t d -a -n 7 sshd | grep -i ssh-2
521008 OpenSSH-2.0*,OpenSSH-2.1*,OpenSSH_2.1*,OpenSSH_2.2*

# dd if=./sshd bs=1 skip=521008 count=11 | od -A n -c
11+0 records in
11+0 records out
   O   p   e   n   S   S   H   -   2   .   0
11 bytes (11 B) copied, 0.000208606 s, 52.7 kB/s

# dd if=./sshd bs=1 count=521008 of=sshd.1
521008+0 records in
521008+0 records out
521008 bytes (521 kB) copied, 1.46733 s, 355 kB/s

# dd if=./sshd bs=1 skip=521008 count=11 of=sshd.2
11+0 records in
11+0 records out
11 bytes (11 B) copied, 0.00032878 s, 33.5 kB/s

# dd if=./sshd bs=1 skip=521008 count=999999999 of=sshd.3
131808+0 records in
131808+0 records out
131808 bytes (132 kB) copied, 0.368016 s, 358 kB/s

# od -A n -c sshd.2
O   p   e   n   S   S   H   _   2   .   0

# ls -l sshd.2 -rw-r--r-- 1 root root 11 May  6 14:11 sshd.2
# print -n ItsHidden > sshd.2
# ls -l sshd.2 -rw-r--r-- 1 root root 11 May  6 14:12 sshd.2

# cat sshd.* > sshd.new

# chmod 755 ./sshd.new
# cp /usr/sbin/sshd /usr/sbin/sshd.bak
# rm /usr/sbin/sshd
# cp /tmp/sshd.new /usr/sbin/sshd

# service sshd stop
# ps aux | grep -i sshd
# kill -9 <pid_sshd>
# service sshd restart
# telnet localhost 22

#!/bin/bash
sleep 10
service sshd stop
sleep 10
sed -i.bak.$(date +%F.%s) 's/OpenSSH_5.3/Blocked_9.9/g' /usr/sbin/sshd
sleep 10
service sshd start

nohup ./test.sh & exit 0

echo "Hello" | nc [Server IP here] 22