Network Security Aspects Notes & Important Points
• Malware is a software developed with an intention to damage computer hardware, software, steal data, or cause any other trouble to a user.
• A virus is a piece of software code created to perform malicious activities and hamper resources of a computer system.
• The Worm is also a malware that incurs unexpected or damaging behaviour on an infected computer system.
• Worms are standalone programs that are capable of working on its own.
• Ransomware is a type of malware that targets user data.
• Ransomware either blocks the user from accessing their own data or threatens to publish their personal data online and demands ransom payment against the same.
• Trojan is a malware, that looks like a legitimate software and once it tricks a user into installing it, it acts pretty much like a virus or a worm.
• Spyware records and sends the collected information to an external entity without the consent or knowledge of a user.
• An adware displays unwanted online advertisements using pop-ups, web pages, or installation screens.
• A keylogger makes logs of daily keyboard usage and may send it to an external entity as well.
• The on-screen keyboard is an application software that uses a fixed QWERTY key layout.
• Online virtual keyboard is a web-based or a standalone software with a randomised key layout every time it is used.
• A malware can take many routes to reach your computer, which include: Downloaded from the Internet, Spam Email, using infected Removable Storage Devices, and network propagation.
• An antivirus software is used to detect and remove viruses and hence the name anti-virus.
• Antiviruses now come bundled with the prevention, detection, and removal of a wide range of malware.
• Some of the prominent methods of malware identification used by an antivirus include: Signature-based detection, Sandbox detection, Heuristics.
• Any unwanted data, information, email, advertisement, etc. is called Spam.
• HTTP (Hyper Text Transfer Protocol) and HTTPS (Hyper Text Transfer Protocol Secure) are a set of rules or protocol that govern how data can be transmitted over the World Wide Web.
• Firewall is a network security system designed to protect a trusted private network from unauthorised access or traffic originating from an untrusted external network.
• There are two basic types of firewalls — Network Firewall and Host-based Firewall.
• A computer cookie is a small file or data packet, which is stored by a website on the client’s computer.
• Cookies are used by the websites to store browsing information of the user.
• Hackers/Crackers find loopholes and vulnerabilities in computer systems or computer networks and gain access to unauthorised information.
• If a hacker uses its knowledge to find and help in fixing the security flaws in the system, its termed as White Hat hacker.
• If hackers use their knowledge unethically to break the law and disrupt security by exploiting the flaws and loopholes in a system, then they are called black hat hackers.
• The grey hats take system security as a challenge and just hack systems for the fun of it.
• The Denial of Service (DoS) attack floods the victim resource with traffic, making the resource appear busy.
• Distributed Denial of Service (DDoS) is an attack, where the flooded requests come from compromised computer (Zombies) systems distributed across the globe or over a very large area.
• Network Intrusion refers to any unauthorised activity on a computer network.
• Snooping is the process of secret capture and analysis of network traffic by malicious users.
• Eavesdropping is an unauthorised realtime interception or monitoring of private communication between two entities over
a network.
