Lesson 11
Date: 4/17/2019
Linux Network Security
Linux System Administration
Identifying SSH login attacks in the system logs
Exercise
On
testub
VM, check the lines in log file
auth.log
and see ssh login attempts to user account
jerry
:
grep jerry /var/log/auth.log | grep auth
See the successfull attempt to login:
grep jerry /var/log/auth.log | grep -E -v '(error|[Ff]ail)'
How systems get compromized
Exercise: SSH brute force attack
Exercise: Log check for login attempts
Exercise: TCP wrappers
Exercise: denyhosts
Stack overflow
Exercise with Stack overflow
Package upgrades and verification
Open Ports List exercise
Closing Ports
IP filtering firewalls (iptables)
Building iptables rules
Simple iptables script
Exercises with iptables
Port scanning exercises
System Integrity Checks
GNUtar exercises
References
Take me to the Course Website