Introduction
Windows group policies are infrastructures that allow an administrator to set up configurations specific to a computer, a user, or a group of users. These configurations can be used to enhance a network’s security by disabling insecure features, such as removable USB drives or the outdated TLS protocol. They can also be used to set up scripts that would execute on computer startup and shutdown as computer settings, and user logon and logoff as user settings. Another example of computer settings is the password policy, accessible through Windows settings, Security settings, and Account settings submenus, it allows one to enforce stricter limitations on password generation and usage. By adjusting policies within it, one can require users to choose sufficiently complex passwords, change them after a set amount of time, and forbid the reuse of older passwords. A minimum length of 8 characters with enforced complexity requirements, a maximum age of 90 days, and at least 4 previous passwords stored to prevent reuse would make a reasonable basic password policy that can be further adjusted according to the organization’s needs.
Windows Logs
Windows keeps logs for five categories of events: application, security, setup, system, and forwarded events. The security event log contains events such as user logon and logoff, policy changes, and similar events related to users acquiring and using elevated privileges.
Iptables
Iptables is a Linux command-line utility that allows one to set up network packet filtering rules. To drop all SSH connections from a specific IP address, one has to write the following rule: iptables -A INPUT -p tcp -s xxx.xxx.xxx.xxx –dport 22 -j DROP, where xxx.xxx.xxx.xxx stands for the desired IP address (Unix.com, 2022). Since SSH servers run on port 22 by default, this rule will work in most cases. However, if the particular machine’s SSH server has been reconfigured to a different port, the rule would have to be altered accordingly.
Reference
UNIX.com. (2022). Iptables (8) [linux main page]. Web.