An Overview Of Unix In Cybersecurity
By Tom Seest
Unix is an interactive multi-user operating system written in C programming language. It includes a shell, command line interpreter, system programs, and many small utility applications.
Unix systems rely on file permissions, which grant different users access to files and directories within the filesystem. These permissions are composed of nine permission bits, set user and group ID bits, plus a sticky bit for extra assurance.
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Table Of Contents
An operating system in computing refers to a set of programs that coordinate all the hardware parts of your computer to perform useful tasks for you. It manages memory, disk drives, keyboards, and monitors that you use when working with it.
The kernel, the core operating system software, allocates time and memory to each program running on your computer and manages all internal details. It also handles file storage, communication, and execution of system calls.
Multitasking on a computer with this type of system is ideal, as it permits multiple users to log on simultaneously while keeping each individual’s data secure. It runs on any hardware platform and is used by numerous entities, from businesses and educational institutions alike.
Another advantage of UNIX is its portability, meaning you can take the code you’ve written and modify it for different systems. Furthermore, its features like pipes and filters enable complex programs from simpler ones.
UNIX is an open source operating system that runs on a variety of hardware platforms, from servers and desktops alike. It has become the de facto standard for computer operations and serves as the basis for other operating systems like Linux.
Flexible and customizable, it provides a range of security tools. These include root accounts, file permissions, and an advanced virus-scanning system.
Before you can get started with UNIX, it is necessary to become familiar with some basic commands. These commands make interacting with the operating system simpler and more efficient.
For example, pressing Ctrl (Control) + u will delete an entire line while pressing Ctrl (Control) + c will abort a program. Furthermore, the shell keeps track of your previous commands so you can reuse them again with ease.
You can quickly change the name of a command or file by typing some letters and pressing the tab key. This feature, known as filename completion, allows it to automatically complete any remaining parts of the name if it detects more than one that starts with those particular letters.
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Root accounts possess the highest level of access a computer system can grant. Anyone with this password has the power to alter system files, permanently alter software applications, and more – but despite their privileged position, there are steps you can take to safeguard your system against root account attacks.
First and foremost, root accounts should not be used for unauthorized or non-administrative tasks. This is a fundamental principle of information security that provides one of the best safeguards to safeguard your network and devices.
Next, it is essential to protect root accounts by enabling multifactor authentication (MFA). This will shield them from abuse or compromise by attackers and make it harder for hackers to steal their passwords.
Finally, always ensure you limit the number of individuals with root access to a system. This is especially critical if your setup has numerous resources as it could easily be exploited by malicious actors.
There are various tools available to limit the capabilities of root accounts on computer systems, such as Linux’s SELinux security framework and others. While these measures tend to be employed by security-conscious enterprises with dedicated security teams, they can be beneficial for organizations of all kinds.
To protect your root accounts, implement a privileged access management solution. These tools can monitor root user activity and notify security officers when they engage in inappropriate behaviors.
Privileged accounts are essential for many businesses, as they grant administrators access to systems and data that would otherwise remain inaccessible without them. Unfortunately, they also carry significant risks.
Employees often share privileged accounts, leaving them vulnerable to misuse and hacking. Furthermore, passwords associated with these accounts may leak when an employee changes jobs, as they can often be found in emails or notes.
These accounts are usually disabled until an emergency arises, and certain users require privileged access to restore systems or respond to cyber incidents. Unfortunately, these accounts can be abused just like other privileged ones are, making it essential to deploy a privileged account management solution.
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File permissions are an integral part of cybersecurity, helping you guard against malware encrypting your files. They also protect your network and shield you against ransomware attacks.
On a Linux system, different users have different levels of permissions to files and directories. These permissions are set by the System Administrator – either the computer owner or IT administrator for an entire network of computers.
To view file permissions, use the ls command with a -l option, which displays them as strings of letters on the left side of your screen. Each one begins with “d” as if it were a directory and then contains three characters that indicate who has read, write, and execute permissions, while group and world sets are read-only.
Typically, the user who owns a file is its creator and responsible for maintaining it. They can grant other users access to that same file by creating different groups and assigning files and directories to those groups.
However, there may be instances when it’s necessary to restrict the permissions of a file or folder to other users only. For instance, making sure only home users have access to music and images or working at an office where only certain individuals require access to specific folders, this approach can be beneficial.
A typical Linux file permission looks like this: rw-r-x, with the first character being a letter and the other two characters being hyphens. The initial hyphen indicates read permissions for all users (owner, group, and world sets), while the following three indicate write permission for the user and world set alike.
Another method for displaying file permissions is using octal notation. This format is similar to symbolic notation but more compact and versatile; it can be employed in many instances where a traditional format may not be ideal.
On a Linux system, files have three permission sets: read (r), write (w), and execute (x). Additionally, you can set the set user ID and group ID bits, which alter the identity of any process that executes a file with those bits set.
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In cybersecurity, virus scanning refers to the technology used to detect and eliminate viruses and other malware from a computer. Antivirus software typically scans files and documents for signs of infection as well as searches for suspicious processes running within the network.
The most widely used method for virus detection is signature-based scanning. In this approach, the software scans all files in memory and on disk for a code snippet that will uniquely identify each file as malicious.
Another form of virus scanning is heuristic analysis. Heuristic detection examines a file’s appearance and functionality, which may be more efficient than signature-based analysis.
The heuristic analysis utilizes signature- and behavioral-based recognition techniques to detect malicious files. This type of analysis is especially effective at spotting worms, spyware, and ransomware.
Virus scanning is an integral component of all cybersecurity systems, so it’s essential to select a reliable antivirus solution with excellent detection rates and a user-friendly interface. Furthermore, the program should offer support services if needed.
Be mindful that many antivirus programs use a lot of system resources during scans, which could adversely affect your device’s performance. To mitigate this issue, schedule scans for times when you won’t need your computer or other devices.
When performing a scan, be aware that it may take some time to complete. During this time, your device could be shut down or otherwise inaccessible.
When a scan identifies a potential threat, it will typically quarantine it until you make your decision about whether or not to remove it.
To make the decision easier, most antivirus software will offer a recommended course of action. This could be as straightforward as removing the file or more complex, like keeping it in quarantine pending further analysis.
Linux machines come with a range of high-quality antivirus tools to protect them from malware and viruses. Many are free or inexpensive, while others require you to spend some money. These range from command-line programs and GUI applications running on top of the Linux operating system itself.
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