Network Security | Question
Network Security Interview Questions for Experienced
1. What is Malware?
A malicious software is a harmful computer program that hackers use to wreak destruction and gain access to sensitive information. Microsoft defines malware as any software that damages a single computer, server, or computer network. It refers to software rather than the manner in which it was developed. Because malware is employed for a particular purpose rather than a specific technology or tactic, it is distinguished by its functionality rather than its origin.
All instances of malware are also instances of viruses, but not every instance of malware is an instance of a virus (because viruses are just one type of malware).
2. What is Intrusion Prevention System in network security?
An intrusion protection system (IPS) is a network security device (either hardware or software) that monitors a network for illegal activity and blocks, blocks, or drops it if it occurs, in addition to reporting it.
An IDS, which merely detects malicious activity without taking action, is more advanced than an intrusion prevention system (IPS). A next-generation firewall (NGFW) or unified threat management (UTM) solution may include an intrusion prevention system (IPS). Strong enough to examine a large volume of traffic without slowing down network performance, they are amongst the most common network security solutions.
3. What is network encryption?
SSL (also known as transport layer security [TLS]) is the standard network protection technology used to symbolise a secure connection in a user's internet browser (the padlock). Network data protection standards SSL (secure sockets layer) and Layer 2 VPN (virtue layer VPN) have become common worldwide thanks to their recognisable sign. They are utilised by many businesses that desire to ensure their safety and security as well as their internal networks, backbone networks, and virtual private networks (VPNs).
Network-level data encryption is a fairly blunt weapon at the low level. Information flowing over the network is almost completely oblivious to the value of the data, and this context is almost always set to protect everything. Even when the “protect everything” strategy is used, network traffic patterns can provide valuable information to potential attackers.
Network data encryption is only part of a complete data security strategy. An organisation must also consider the risks associated with data generation and consumption to ensure the best possible result. Driving on the freeway at high speed is much easier than in a parking lot or private garage!
4. What are the benefits of a firewall?
- A firewall must monitor all data moving through a network to ensure it is not infected with malicious code. It monitors every packet and determines whether it contains any dangerous content. If it does, it blocks it immediately.
- A Trojan is harmful to a user because it hides on a computer and monitors everything you do. It may see everything you do on your computer, including your personal information. When your computer behaves strangely, it is probably because it is being controlled by a Trojan. A firewall will block Trojans immediately once they enter your system.
- Computer hackers on the internet look for vulnerable computers in order to carry out illegal acts. When they find such computers, they will begin to execute harmful applications such as computer viruses. There may also be unknown individuals looking for open internet connections, such as the neighbours. In order to prevent these incidents, it is critical to be protected by a firewall security system.
- A firewall can block certain hosts and services from accessing the system in order to prevent hackers from exploiting them. The best course of action is to block these hosts from accessing the system. If a user feels that they need protection from these types of unwanted access, this access policy may be enforced.
- Privacy is one of the primary concerns of an online user. Hackers look for details about the user's privacy in order to learn about it. A firewall, for example, can block many of the services offered by a website such as the domain name service and the finger. As a result, hackers are unable to obtain user information. Firewalls may also block DNS information, preventing the attacker from obtaining the website's name and IP address.
5. What is a Proxy firewall?
A proxy firewall protects network resources by filtering packets at the application layer, rather than the network or transport layers. However, applications may slow down and functionality may be affected by using one.
Traditional firewalls do not focus on decrypting traffic or inspecting application protocol traffic. As a result, only a small portion of the threat landscape is covered by IPSs or antivirus solutions.
Proxy servers act as a conduit between two networks, providing an intermediary between computers and servers on the internet so that secure data may be passed back and forth. A proxy server blocks, filters, archives, and manages requests from devices in order to protect networks from cyberterrorism and unauthorised access. It decides which traffic is permitted and denied and detects signs of a cyberthreat or malware intrusion.
6. What is a UTM firewall?
A single device within your network provides multiple security functions and services. With UTM, your network users are protected with a variety of security functions, including antivirus, content filtering, email and web blocking, and anti-spam, to name a few.
Bringing together all of an organisation's IT security services into one device may simplify the protection of the network. It is possible to monitor all dangers and security-related activity with a single pane of glass through your business. You get comprehensive, simplified access to all aspects of your security or wireless framework with this approach.
7. Explain Stateful Inspection?
Stateful inspection also known as dynamic packet filtering is a firewall technology that monitors the state of active connections and allows network packets through the firewall based on this information. In contrast to stateless inspection, stateful inspection is well suited to static packet filtering and can also support UDP and similar protocols. However, it can also handle TCP and other protocols like it.
Check Point Software Technologies (CPST) developed the technique for stateful firewall technology in the early 1990s to overcome the limitations of stateless firewall technology. Since then, stateful firewall technology has become a prevalent industry standard and is one of the most popular firewall technologies in use today.
8. Why does an Active FTP not work with network firewalls?
A firewall is established by typing a port number (or a range of port numbers) and an incoming or outgoing direction of traffic (active or passive FTP) into the rules. These two types of traffic require two different rules. A firewall must have two different rules for active FTP in order to allow these two kinds of traffic. The initiator in a push is external, whereas the initiator in a pull is internal. Active FTP is a unique application of ftp that requires different configurations.
9. What is a DDoS attack?
An internet traffic flood is used to prevent users from accessing connected online services and sites in a DDoS Attack. DDoS attacks are often motivated by a range of reasons, including hacktivists seeking to damage a company's servers for fun or to demonstrate cyber vulnerabilities, as well as individuals who are annoyed by a company's services. A competitor may disrupt or shut down another business's online operations to steal business away or to obtain money through extortion. A hostageware or ransomware infection on their servers may be forced them to pay a large financial sum to have the damage repaired.
A financially motivated distributed denial-of-service attack is one in which a competitor disrupts or shuts down another business's online operations to steal business away in the meanwhile. Even the largest multinational corporations are not immune to being "DDoS'ed", rising DDoS attacks. An enormous attack occurred in February 2020 on Amazon Web Services (AWS), which toppled an earlier attack on GitHub two years before. DDoS attacks can lead to a drop in legitimate traffic, loss of business, and reputation damage.
10. What is Ransomware?
A ransomware threat encodes data, usually encrypting it, until the victim pays a ransom to the attacker. In many situations, the ransom demand comes with an expiration date. If the victim doesn’t pay in time, the data is irretrievable or the ransom is increased, the demand is fulfilled. Ransomware attacks are common these days. Businesses all over North America and Europe are victims of ransomware.
Cybercriminals target consumers and enterprises of all stripes. In addition to the FBI, several government agencies, including the No More Ransom Project, recommend avoiding paying the ransom to avoid encouraging the ransomware cycle. Furthermore, half of those who pay the ransom will likely be targeted again by ransomware, especially if the infection is not removed from the system.
11. Explain the basic working of network security?
A network security measures and procedures, hardware and software solutions, and set of rules and standards for network access and security. The phrase describes all the approaches to safeguarding a network and its data from intrusions and other dangers.
Network security involves blocking access to computer programs and networks, identifying and eliminating viruses, protecting data through encryption, and monitoring traffic.
An effective network security plan safeguards client data, keeps shared information secure, and ensures reliable network access and performance. It reduces overhead expenses and safeguards organisations from costly data breaches or other security incidents. Companies must protect themselves from cyberthreats by ensuring legitimate access to systems, applications, and data.
12. What is Spyware?
Spyware is a kind of malware that enters your computer or mobile device and gathers information about you, including the sites you visit, the stuff you download, your username and password, payment information, and email correspondence. It's no surprise that spyware is sneaky. It sneaks into your computer without your permission or knowledge and joins your operating system. You may even agree to the terms of a seemingly legitimate program without reading the fine print, in which case spyware may be installed on your computer. Despite the various methods spyware can utilise to infiltrate your computer, the method of operation is always the same—it runs quietly in the background, staying secret, gathering data or monitoring your activity in order to inflict harm on your machine or your activities. Even if you discover its undesirable presence on your machine, Spyware does not have an easy uninstall feature.
13. What is Adware?
Adware is a type of malware that displays unwanted advertisements on your computer or mobile device. Adware is commonly installed on computers and mobile devices without the user's knowledge. When users try to install legitimate applications, adware is often activated. Some pop-up windows display advertisements without collecting data or infecting your computer, but some pop-up windows are designed to target you with customised adverts. It is possible for adware to direct you to malicious websites and infected pages via advert links, putting you at risk of computer viruses.
14. What is Phishing?
Some pop-up windows display advertisements without collecting data or infecting your computer, but some pop-up windows are designed to target you with customised adverts. It is possible for adware to direct you to malicious websites and infected pages via advert links, putting you at risk of computer viruses. A phishing email is sent to trick the victim into giving up sensitive information, such as credit card numbers and logins. This type of cybercrime is common, and everyone should be aware of it. It is accomplished through email. Malware can also be installed on a victim's machine in a phishing attack.
15. What is the use of a VPN?
A VPN service can increase your online security, anonymity, and freedom, all without having to sacrifice any of them. It's a straightforward and quick method of doing so. When using the internet, your device constantly sends data to other sites in order to exchange information. A VPN creates a secure tunnel between your device (e.g. mobile or laptop) and the web. Using a VPN, you may send data across a secure, encrypted connection to an external server: the VPN server. From there, your information will be delivered to its destination on the web. Securing your data and hiding your online identity are just a few of the advantages of rerouting your internet traffic through a VPN server.
16. What is traceroute?
By using tools for network diagnostics, known as traceroute, administrators can trace the path data packets take from their source to their destination, thus finding connectivity problems. On a Windows machine, tracert is the command; on Linux and Mac, it is traceroute. Traceroute and tracert both function similarly; they trace the route data takes from one location in a network to a specific IP server. Traceroute records the name and IP address of each intermediate device that a data packet must traverse in order to reach its destination. It then provides the round-trip time (RTT) and the device name. You can use traceroute to determine where a problem is occurring, but it alone can't tell you if there is one. To help you determine if there is a problem, ping can be used. Imagine that you're trying to visit a website and pages take a long time to load. If you use traceroute to determine where the longest delays are occurring, you can determine where the problem is.
17. What is Port Scanning?
A port scan is a method for discovering which ports are open on a machine or network. To test whether someone is at home before knocking on the door, you could port scan the system or network. It reveals which ports are open and accepting information, as well as shows if firewalls are installed between the source and target. Fingerprinting is the term used to describe this technique. As a result, it can also be an ideal reconnaissance tool for attackers seeking to discover a network’s weakest point of entry. It is also used to test network security and the firewall's strength. Port scanning is a standard technique employed by hackers to discover open doors or weak spots in a network. A port scan attack may help cyber criminals discover available ports and determine whether they are sending or receiving data. It may also reveal whether security systems like firewalls are being used by a company. When hackers contact a port, the response they receive determines whether the port is being used and whether potential vulnerabilities exist. A business may also scan ports using this technique and analyze the response for potential vulnerabilities. They may then employ tools like IP scanner, network scanner (Nmap), and Netcat to ensure the security of their network and systems.
18. What is port blocking within LAN?
An Internet Service Provider (ISP) blocks Internet traffic by using the port number and transfer protocol. Blocking certain types of ports within a local area network is known as port blocking. Blocking ports on plug-and-play devices such as USB flash drives, removable devices, CD/DVD/CD-ROM, floppy, and mobile devices like smartphones is among the reasons for port blocking.
Suppose your network has DHCP service enabled. When a user connects their laptop to your device, they can obtain your IP address from the DHCP and gain access to your network resources. This is why you should turn on port security if you can to prevent ports from conflicting with MAC addresses and allowing anonymous users to obtain an IP address.
19. What is a Botnet?
A botnet is a group of computers that has been taken over by a bot, or a robot-controlled computer network. Multi-layered computer schemes are often used to infiltrate and assemble a botnet. Massive data theft, server crashes, and malware distribution are just a few of the automated tasks that bots are capable of completing.
A botnet is a group of infected devices used to scam other users or cause disruptions without the victims’ consent. The “what is a botnet attack and how does it work?” query is appropriate here. To assist you in understanding how botnets are created and employed, we'll demonstrate how they're made.
20. What is secure remote access?
A secure remote access process or solution may include security procedures such as VPN, multifactor authentication, and endpoint protection, among others. It is designed to keep crooks away from an organisation's digital assets and safeguard sensitive information. Remote access may be protected via VPN, multifactor authentication, or endpoint protection.
Today's IT environment, which is facing a rapidly changing threat landscape and the growing number of remote workers as a result of the Covid pandemic, demands secure remote access. In order to succeed, users must be educated, strong cybersecurity policies must be implemented, and best security hygiene practices must be developed.
Conclusion
Network security is the protection of information and data in a network. It is the protection of data that is stored on a computer or network server from unauthorized access, modification, or theft. Network security is an important part of protecting your organization's data and systems. It can help to prevent cyber attacks and protect critical infrastructure from damage.
In order to be successful in a security interview, you need to have a solid understanding of the basics of security. This includes understanding the basic concepts and principles of security, including how to secure your network and how to protect your data. You also need to know what types of threats you face, how you can detect and prevent them, and how you can protect yourself from them. In addition, you should also understand what types of vulnerabilities are present in your system and how they can be exploited.
For example, if you have a lot of sensitive data stored on your computer or network, this might make it easier for hackers to gain access to your system. In this case, it is important that you understand the risks and benefits of different types of systems.
Finally, it is important that you know
how to perform various tasks on your system and how they can be
performed safely. This includes setting up network settings (for
example, firewall rules), configuring services (for example, web browser
or file transfer programs), managing devices (for example, computers or
printers), and managing user accounts (for example, logging into social
media accounts).
Firewall
A Next-Generation Firewall offers far improved security with in-line deep packet inspection, an intrusion prevention system, TLS/SSL encrypted traffic inspection, website filtering, QoS/bandwidth management, antivirus inspection and third-party identity management integration.
Advantages of using Firewall
- Firewall acts as a barrier between trusted internal network and untrusted external networks preventing from unauthorized access, data breaches and cyber attacks.
- Firewalls provide the ability to enforce the access control lists allowing only trusted users and devices to connect to the network preventing intrusions and malware infections.
- Firewalls can log and monitor traffic providing valuable insights into network activities helps in identifying and responding to suspicious activities and network threats.
- It helps to block malware and other harmful software from entering a network by filtering content and preventing it from reaching endpoints.
- Firewalls are equipped to detect and mitigate DDoS attacks which overhealms the network with traffic and it also supports VPN.
Disadvantages of using Firewall
- Latency is introduced by firewall that degrades network performances, especially when handling large volumes of traffic or when performing deep packet inspection.
- Firewalls provide a boundary defense but are not a comprehensive security solution.
- They do not protect against all types of attacks such as insider threats, phishing, or attacks on endpoints that are already inside the network.
- High quality firewalls especially hardware based ones, can be expensive to purchase, install, and maintain, cost can be prohibitive for small organizations or individuals.
- Relying solely on a firewall can lead to a false sense of security.
- Basic firewalls may not provide application level filtering, which means they can't detect and block malicious activity within permitted traffic, such as attacks that hide within HTTP or HTTPS traffic.
Source:
https://www.interviewbit.com/network-security-interview-questions/
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