The operating system is the environment where your system’s applications run. In the operating system any kind of cyber-attacks could compromise the security of the application. Today's operating systems are more technically advanced and feature-rich than ever before, which makes them very much useful to the consumers but also adds to security vulnerability. To put it in the most basic terms, a computer system vulnerability is a flaw or weakness in a system or network that could be exploited to cause damage, or allow an attacker to manipulate the system in some way.
Accounts
There should be limitations on the number of user accounts on the server computers. All users should log on with user accounts that has the absolute minimum permissions which are necessary to perform the simple tasks and nothing more. Doing so provides protection against malicious attacks. For information security principle of least privilege is best idea. In the principle of least privilege is the idea that any user, programmer, or process have only enough and minimum privilege necessary to perform its functions.It applies to end users, systems, processes, networks, databases, applications, and every other aspect of an IT environment.
For eg., with the principle of least privilege, there is an employee whose job is to enter information into a database. If malware attacks into that employee’s computer or if the employee clicks on some random links or a phishing email then the malicious attack is limited to making database entries. If that employee has been using root access privileges then the infection can spread system-wide.
Network Service
Using multi-factor authentication. Segmented networks enable the setup of least privileged access across zone boundaries. For eg., a company may create a subnet for its printers, or make a segment reserved for storing data.
Isolating parts of a network limits a threat’s ability to move freely through the system. If a section of the network gets breached, other segments are not compromised.
A data loss prevention solution is an essential part of email security. spam filters can separate the spam messages from regular mail and delete them eventually, this will take time.
File System
Access to resources is denied for everyone except for the users to whom access is granted explicitly. You can deny read and write permissions for all directory structures for all users. Only users to whom these permissions are granted explicitly have access to the directories and files. This also protects any resources that were overlooked by an administrator.
System Integrity
Build production systems from a known and repeatable process to ensure system integrity. A multilevel security allows the classification of data and users based on a system of hierarchical security levels combined with a system of non-hierarchical security categories.
A multilevel-secure security has two goals first is, the controls must prevent unauthorized individuals from accessing information at a higher classification than their authorization. Second, the controls must prevent individuals from declassifying information.
Use available third-party auditing software to check the system integrity.
Back up the system resources on a regular basis.
