Class 12 Computer Science — Chapter 12: Security Aspects

Understand the fundamental concept of network security, which involves protecting devices and data from illegitimate access or misuse. This includes recognizing what constitutes a threat and a vulnerability in a connected system.

Define Malware (Malicious Software) as software intentionally developed to damage hardware, steal data, or cause harm. Recognize that it is a broad category encompassing various types like viruses, worms, and trojans.

Define what a computer virus is, how it functions by inserting its code into host programs (executable files), and that it requires human action to spread. Understand its purpose, such as corrupting files or stealing data.

Understand that a worm is a standalone malware program that, unlike a virus, does not require a host. A key characteristic is its ability to replicate and spread independently across networks without human intervention.

Define ransomware as a type of malware that denies a user access to their own files, typically by encrypting them, and demands a ransom payment for their release. Be familiar with examples like WannaCry.

Define a Trojan as malware disguised as a legitimate, harmless program. Understand that it tricks users into installation, does not self-replicate, and can create 'backdoors' for unauthorized system access.

Differentiate between Spyware (secretly gathers user information), Adware (displays unwanted ads for revenue), and Keyloggers (records keystrokes to steal sensitive information like passwords).

Identify and understand the common channels through which malware spreads, such as internet downloads, spam email attachments, infected removable storage devices (like pen drives), and automatic network propagation.

Recognize the common signs of a malware infection (e.g., pop-ups, slow performance, unknown programs) and learn the essential preventive measures, including using updated antivirus software, regular data backups, using firewalls, and practicing safe browsing.

Understand the security advantage of an online virtual keyboard over a standard on-screen keyboard. The virtual keyboard randomizes its key layout, making it difficult for keylogger software to record sensitive input like passwords.