Cyber Security Interview Questions

Some common cyber threats and attacks are malware, phishing, ransomware, denial-of-service, botnet, cryptocurrency hijacking, social engineering, and advanced persistent threats.

Malware is any malicious software that can harm or compromise a system or network, such as viruses, worms, trojans, spyware, adware, etc.

Phishing is a fraudulent technique of sending emails or messages that appear to be from legitimate sources, but are actually designed to trick the recipients into revealing their personal or financial information, or clicking on malicious links or attachments.

Ransomware is a type of malware that encrypts the files or data of a system or network, and demands a ransom from the victims to restore access or prevent deletion.

Denial-of-service is an attack that aims to disrupt or overload the normal functioning of a system or network, by sending a large amount of traffic or requests, or exploiting a vulnerability.

Botnet is a network of compromised devices that are controlled by a hacker or a group of hackers, and can be used to launch various cyber-attacks, such as spamming, phishing, denial-of-service, etc.

Cryptocurrency hijacking is a cyber-attack that involves using the computing resources of a system or network to mine virtual currencies, such as Bitcoin, Ethereum, Monero, etc., without the consent or knowledge of the owners.

Social engineering is a psychological technique of manipulating or influencing people into performing certain actions or divulging confidential information, such as passwords, bank details, etc.

Advanced persistent threats are stealthy and sophisticated cyber-attacks that target specific organizations or individuals, and persist for a long period of time, often using multiple vectors and stages.

The elements or components of cyber security are application security, information security, network security, operational security, disaster recovery, and end-user education.

Application security is the process of adding security features to applications during the development phase, to prevent or mitigate cyber-attacks, such as input validation, encryption, authentication, authorization, etc.

Information security is the process of protecting the confidentiality, integrity, and availability of data, both in transit and at rest, from unauthorized access, use, modification, or destruction, using techniques such as encryption, hashing, digital signatures, access control, etc.

Network security is the process of protecting the infrastructure and devices of a network from unauthorized access, intrusion, or attack, using techniques such as firewalls, antivirus, VPN, IDS, IPS, etc.

Operational security is the process of implementing policies, procedures, and best practices to ensure the security of the operations and assets of an organization, such as risk assessment, incident response, audit, compliance, etc.

Disaster recovery is the process of restoring the normal functioning of a system or network after a cyber-attack or a natural disaster, using techniques such as backup, restore, failover, etc.

End-user education is the process of training and raising awareness among the users of a system or network about the cyber security risks and threats, and how to prevent or avoid them, such as using strong passwords, avoiding phishing emails, updating software, etc.

Symmetric encryption is a type of encryption that uses the same key for both encryption and decryption of data, such as DES, 3DES, AES, RC4, etc. Symmetric encryption is faster and more efficient, but less secure, as the key has to be shared and protected between the parties.

Asymmetric encryption is a type of encryption that uses different keys for encryption and decryption of data, such as RSA, Diffie-Hellman, ECC, etc. Asymmetric encryption is slower and more complex, but more secure, as the keys do not have to be shared and can be generated independently by the parties.

IDS is Intrusion Detection System, which is a device or software that monitors the network or system for any suspicious or malicious activity, and generates alerts or reports for the administrator. IDS only detects intrusions, but does not prevent or block them.

IPS is Intrusion Prevention System, which is a device or software that monitors the network or system for any suspicious or malicious activity, and takes actions to prevent or block them, such as dropping packets, terminating connections, or blocking IP addresses. IPS not only detects intrusions, but also prevents or blocks them.

The CIA triad is a model or framework that defines the three main objectives or principles of cyber security, which are Confidentiality, Integrity, and Availability.

Confidentiality is the principle of ensuring that the data or information is accessible only to the authorized parties, and is protected from unauthorized access, disclosure, or theft, using techniques such as encryption, access control, authentication, etc.

Integrity is the principle of ensuring that the data or information is accurate, complete, and consistent, and is protected from unauthorized modification, alteration, or corruption, using techniques such as hashing, digital signatures, checksum, etc.

Availability is the principle of ensuring that the data or information is available and accessible to the authorized parties, whenever and wherever needed, and is protected from unauthorized denial, disruption, or destruction, using techniques such as backup, restore, redundancy, load balancing, etc.

VA is Vulnerability Assessment, which is the process of identifying and evaluating the vulnerabilities or weaknesses of a system or network, using automated tools or manual techniques, and generating a report or a score of the vulnerability level. VA is a proactive and preventive measure, which aims to find and fix the vulnerabilities before they are exploited by the attackers.

PT is Penetration Testing, which is the process of simulating or mimicking a real-world cyber-attack on a system or network, using the same tools and techniques as the attackers, and generating a report or a feedback of the impact and severity of the attack. PT is a reactive and corrective measure, which aims to test and validate the security posture and resilience of the system or network against the attacks.

A three-way handshake is a method or protocol of establishing a TCP (Transmission Control Protocol) connection between two devices or hosts, by exchanging three messages or packets, namely SYN, SYN-ACK, and ACK.

The first message or packet is SYN, which is sent by the client to the server, to request or initiate a connection, and to synchronize the sequence numbers.

The second message or packet is SYN-ACK, which is sent by the server to the client, to acknowledge or accept the connection request, and to synchronize the sequence numbers and the acknowledgment numbers.

The third message or packet is ACK, which is sent by the client to the server, to confirm or finalize the connection establishment, and to acknowledge the sequence numbers and the acknowledgment numbers.

The response codes that can be received from a web application are the HTTP (Hypertext Transfer Protocol) status codes, which are three-digit numbers that indicate the result or outcome of a request made to a web server. The response codes are divided into five categories, based on the first digit, as follows:

1xx: Informational, which means that the request has been received and is being processed, such as 100 (Continue), 101 (Switching Protocols), etc.

2xx: Success, which means that the request has been successfully received, understood, and accepted, such as 200 (OK), 201 (Created), 202 (Accepted), etc.

3xx: Redirection, which means that the request has been redirected to another location or resource, such as 301 (Moved Permanently), 302 (Found), 303 (See other), etc.

4xx: Client Error, which means that the request has been made by the client, but the server cannot or will not process it, due to some error or mistake on the client's side, such as 400 (Bad Request), 401 (Unauthorized), 403 (Forbidden), 404 (Not Found), etc.

5xx: Server Error, which means that the request has been made by the client, but the server cannot or will not process it, due to some error or failure on the server's side, such as 500 (Internal Server Error), 501 (Not Implemented), 502 (Bad Gateway), 503 (Service Unavailable), etc.

^{Traceroute is a command-line tool or utility that is used to trace or track the route or path that a packet takes from a source device or host to a destination device or host, across a network or the internet.} 

^{Traceroute also displays the time or latency that each hop or node takes to reach the destination, and the number of hops or nodes that the packet passes through.}