Page 86 - Code & Click - 7

SOURCES OF MALWARE

Computer viruses usually spread in one of three ways – from removable media, such as CDs, DVDs,
and pen drives, pirated software; downloads from unauthorised websites; and email attachments.

INDICATIONS OF MALWARE INFECTION
Some common warning signals that indicate a computer is infected by malware are:
• The computer becomes slow and programs take a lot of time to load.
• The hard disk does not allow you to save files, even if there is
enough space available.
• The files stored on the computer get deleted on their own.
• The computer stops responding or restarts frequently.
• The hard disk or other disk drives become unaccessible.
• The web browser opens a different page from the one you
want to open.
• New files and folders keep appearing on the system, but you do not know where they came
from.

TYPES OF MALWARE

Malware has various forms and can infect a computer in different
ways. Types of malware include viruses, worms, trojan horses,
rootkits, fileless malware, ransomware, botnets, adware, spyware,
malvertising, phishing, and more. Let us know more about the
various types of malware.

Virus
A Virus is a software that can replicate itself and cause harm to the operating
system, other application software, or data files in a computer. It can spread
from program to program and disk to disk, manipulating and damaging
valuable data without the user’s knowledge.
A virus normally does not act on its own. Once the infected program is executed or the infected file is
accessed, the virus gets activated and infects other programs and files in the computer system. The
effect of a virus can be harmless, such as the display of pop-up messages, or it can be serious, such
as destroying programs and data.

Types of Viruses

Computer viruses can be classified as:
Boot Sector Virus
A Boot Sector Virus infects boot record program on a hard disk,
responsible for loading the operating system into memory. When
the system is booted with an infected hard disk, the virus enters the
memory and infects all files that are written to or read from the disk.
Michelangelo, Disk Killer, Brain, and Stoned are examples of boot
sector viruses.

84