OS hardening practices
Hi there. In this video, 
we'll discuss operating system, or 
OS, hardening and why it's 
essential to keep the entire network secure. 
The operating system is 
the interface between computer hardware and the user. 
The OS is the first program 
loaded when a computer turns on. 
The OS acts as an intermediary 
between software applications and the computer hardware. 
It's important to secure the OS in each system 
because one insecure OS can 
lead to a whole network being compromised. 
There are many types of operating systems, and they 
all share similar security hardening practices. 
Let's talk about some of 
those security hardening practices that 
are recommended to secure an OS. 
Some OS hardening tasks 
are performed at regular intervals, 
like updates, backups, and keeping 
an up-to-date list of devices and authorized users. 
Other tasks are performed only 
once as part of preliminary safety measures. 
One example would be configuring 
a device setting to fit a secure encryption standard. 
Let's begin with OS hardening tasks 
that are performed at a regular interval, 
such as patch installation, 
also known as patch updates. 
A patch update is a software and operating system, or 
OS, update that addresses 
security vulnerabilities within a program or product. 
Now we'll discuss patch updates provided 
to the company by the OS software vendor. 
With patch updates, the OS should 
be upgraded to its latest software version. 
Sometimes patches are released 
to fix a security vulnerability in the software. 
As soon as OS vendors publish 
a patch and the vulnerability fix, 
malicious actors know exactly where 
the vulnerability is in systems 
running the out-of-date OS. 
This is why it's important for organizations to run 
patch updates as soon as they are released. 
For example, my team 
had to perform an emergency patch to 
address a recent vulnerability 
found in a commonly used programming library. 
The library is used almost everywhere, 
so we had to quickly patch most of our servers and 
applications to fix the vulnerability. 
The newly updated OS should be 
added to the baseline configuration, 
also called the baseline image. 
A baseline configuration is a documented set of 
specifications within a system 
that is used as a basis for future builds, 
releases, and updates. 
For example, a baseline may contain 
a firewall rule with a list of 
allowed and disallowed network ports. 
If a security team suspects 
unusual activity affecting the OS, 
they can compare the current configuration to 
the baseline and make sure that nothing has been changed. 
Another hardening task performed regularly is 
hardware and software disposal. 
This ensures that all old hardware 
is properly wiped and disposed of. 
It's also a good idea to delete 
any unused software applications since 
some popular programming languages 
have known vulnerabilities. 
Removing unused software makes sure that there aren't 
any unnecessary vulnerabilities connected 
with the programs that the software uses. 
The final OS hardening technique that we'll 
discuss is implementing a strong password policy. 
Strong password policies require 
that passwords follow specific rules. 
For example, an organization may set 
a password policy that requires 
a minimum of eight characters, 
a capital letter, a number, and a symbol. 
To discourage malicious actors, 
a password policy usually 
states that a user will lose access to 
the network after entering 
the wrong password a certain number of times in a row. 
Some systems also require 
multi-factor authentication, or MFA. 
MFA is a security measure 
which requires a user to verify their identity in 
two or more ways to access a system or network. 
Ways of identifying yourself include 
something you know, like a password, 
something you have like an ID card, 
or something unique about you, like your fingerprint. 
To review, OS hardening is a set of procedures that 
maintains OS security and improves it. 
Security measures like 
access privileges and password policies 
frequently undergo regular security checks 
as part of OS hardening. 
Coming up, we'll discuss network hardening practices. 
