Newcomer to Cybersecurity: 16 Questions and Answers on Basic Knowledge of Technology Q: What is network security? Answer: Network security means that the hardware, software and data in the network system are protected from being damaged, changed, or leaked due to accidental or malicious reasons. The system can run continuously and reliably, and network services are not affected. Interrupt. Q: What is a computer virus? Answer: A computer virus (ComputerVirus) refers to a set of computer instructions or program codes inserted by a compiler into a computer program that damages computer functions or destroys data, affects the use of the computer, and can replicate itself. Q: What is a Trojan? Answer: Trojan is a remote control software with malicious nature. Trojans are generally divided into a client (client) and a server (server). The client is the console of various commands used locally, and the server is for others to run. Only the computer that has run the server can be fully controlled. Trojans do not infect files like viruses. Q: What is a firewall? How does it ensure network security? Answer: Using a firewall is a method to ensure network security. A firewall refers to a combination of a series of components installed between different networks (such as a trusted intranet and an untrusted public network) or a network security domain. It is the only entry and exit of information between different networks or network security domains. It can control (allow, deny, monitor) the flow of information to and from the network according to the company's security policy, and it has strong resistance to attacks. It is an infrastructure that provides information security services and realizes network and information security. Q: What is a backdoor? Why is there a backdoor? A: Backdoor (BackDoor) refers to a method to gain access to a program or system by bypassing security control. In the software development stage, programmers often create backdoors in the software so that defects in the program can be modified. If the backdoor is known by others, or if it was not removed before the software was released, then it becomes a security risk. Q: What is intrusion detection? Answer: Intrusion detection is a reasonable complement to firewalls, helping the system to cope with network attacks, expanding the security management capabilities of system administrators (including security auditing, monitoring, attack identification, and response), and improving the integrity of information security infrastructure. It collects information from several key points in the computer network system, analyzes the information, and checks the network for violations of security policies and signs of attacks. Q: What is packet monitoring? What does it do? Answer: Packet monitoring can be considered as the equivalent of an eavesdropping telephone line in a computer network. When someone is "listening" to the network, they are actually reading and interpreting the packets transmitted on the network. If you need to send an e-mail or request to download a web page from a computer on the Internet, these operations will pass the data through many computers between you and the data destination. These computers that pass through the information can see the data you send, and the packet monitoring tool allows someone to intercept the data and view it. Q: What is NIDS? Answer: NIDS is the abbreviation of NetworkIntrusionDetectionSystem, that is, network intrusion detection system, which is mainly used to detect the intrusion of Hacker or Cracker through the network. There are two ways to run NIDS, one is to run on the target host to monitor its own communication information, and the other is to run on a separate machine to monitor the communication information of all network devices, such as Hub, router. Q: What is the SYN package? Answer: The first packet of a TCP connection is a very small data packet. SYN attacks include a large number of such packets. Since these packets appear to come from sites that do not actually exist, they cannot be effectively processed. Q: What does encryption technology mean? Answer: Encryption technology is the most commonly used method of security and confidentiality. It uses technical means to turn important data into garbled (encrypted) transmission, and then uses the same or different means to restore (decrypt) after reaching the destination. The encryption technology includes two elements: algorithm and key. The algorithm is the step of combining ordinary information or understandable information with a string of numbers (keys) to generate incomprehensible ciphertext. The key is an algorithm used to encode and decrypt data. In security and confidentiality, the information communication security of the network can be ensured through appropriate key encryption technology and management mechanisms. Q: What is a worm? Answer: Worm originated from the first virus spreading on the Internet. In 1988, 22-year-old Cornell University graduate student Robert Morris (RobertMorris) sent a virus called "Worm" designed to attack the defects of UNIX systems through the Internet. The worm caused 6000 system paralysis, and the estimated loss was 2 million to 60 million US dollars. Due to the birth of this worm, a Computer Emergency Response Team (CERT) was also established on the Internet. Now the worm family has grown to tens of thousands, and most of these tens of thousands of worms come from hackers. Q: What is an operating system virus? What harm does it have? Answer: This virus will use its own program to join the operating system or replace part of the operating system to work. It is very destructive and will cause the entire system to be paralyzed. And because of the infection of the operating system, when this virus runs, it will replace the legal program module of the operating system with its own program fragments. According to the characteristics of the virus itself and the status and role of the legal program module in the operating system being replaced in the operating system, and the way the virus replaces the operating system, the operating system is destroyed. At the same time, this virus is also very infectious to the files in the system. Q: What is the Morris worm? What are its characteristics? A: It was written by Roth Morris, a first-year graduate student at Cornell University. This program has only 99 lines. It takes advantage of the shortcomings in the Unix system. Use the Finger command to check the online user list, then decipher the user's password, use the Mail system to copy and spread its own source program, and then compile the generated code. The original network worm was designed so that when the network was idle, the program "wandered" between computers without causing any damage. When a machine is overloaded, the program can "borrow resources" from idle computers to achieve network load balancing. The Morris worm is not "borrowing resources" but "depleting all resources". Q: What is DDoS? What are the consequences? Answer: DDoS is also a distributed denial of service attack. It uses the same methods as ordinary denial-of-service attacks, but there are multiple sources of attacks. Usually the attacker uses the downloaded tool to infiltrate the unprotected host. After obtaining the appropriate access permissions for the host, the attacker installs the software service or process (hereinafter referred to as proxy) in the host. These agents remain asleep until they receive instructions from their masters to launch a denial of service attack on the specified target. With the widespread use of highly harmful hacking tools, distributed denial of service attacks can launch thousands of attacks on a target at the same time. The power of a single denial-of-service attack may have no effect on a wider-bandwidth site, and thousands of attacks around the world will have fatal consequences. Sweep, welcome attention Official WeChat of Educational Equipment Procurement Network Master the latest and most authoritative information in the education equipment industry Copyright and Disclaimer: â‘ The copyright of all works on this website that indicate "Source: China Education Equipment Purchasing Network" belongs to China Education Equipment Purchasing Network, and may not be reproduced, edited or used in other ways without authorization from this website. 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Newcomer to Cybersecurity: 16 Questions and Answers on Basic Knowledge of Technology
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