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A boot sector virus gains complete control over the Master Boot Record (MBR). MBR is the first sector of the
                 computer hard drive that stores the information about loading the operating system into the main memory.
                 Boot Sector virus replaces the location and information of the Operating System in order to stop it from
                 getting loaded into main memory resulting into errors during booting.Michelangelo, Polyboot.B, Stoned
                 and AntiEXE are some common examples of boot sector virus.

                 Program File Virus

                 A program file infecting virus is a type of malware that infects the executable files of a program with the
                 intention of causing permanent damage or making the program useless. A file-infecting virus overwrites
                 the code or inserts infected code into the source of an executable or program file. When such programs
                 are executed, such virus is activated and damages the files. When a program is run repeatedly, program
                 viruses are deliberately loaded in a program by the developer. A program file infecting virus is also known
                 as a File Injector. Sunday and Cascade are the common examples of program viruses.

                      Do you know?

                      Creeper is the first computer virus that displays “I’m the creeper, catch me if you can!” in 1971 by Bob
                      Thomas. It was just a test to check if self-copy of a program was possible.

                 Worms


                 Worms are the computer programs or algorithms which are alien to the host computer and are designed
                 to purposely slow down the functioning of a computer. Worms replicate inside the system and thus
                 occupy a huge memory space in the storage device. Worms spread more commonly in computers that
                 are connected on network. Examples of worms are Linux. Ballpit, B!gen3, Morris worm, W32/Nimda worm,
                 Mydoom, Sasser etc.
                 Trojan Horse

                 Trojans are infectious programs which silently infect the computer and corrupt the files of a host computer.
                 Such programs often accompany computer games, but unlike worms they don’t replicate themselves.
                 They are active inside the computer when the user is busy interacting with the entertaining programs or
                 with interface like computer games. Some examples of Trojan are Linux.Wifatch, Infostealer.Kronbank, etc.

                 Trojan Horses are often used by hackers as they can enter into the database of a computer system under
                 the guise of some entertaining package. The term “backdoor” is often used for trojan horse. The user
                 interacts with the program and simultaneously the infection takes place behind the interactive interface.
                 Once a trojan horse has infected a computer system, it becomes easier for a hacker to access it remotely
                 and perform unethical operations and steal important information from the infected computer.
                 To prevent a Trojan Horse virus from entering and infecting a computer, it is advisable not to open
                 spams, e-mail attachments or files that may look attractive and luring but have been sent by unknown
                 senders on the Internet.

                 Ransomware

                 Ransomware is a type of malware that encrypts files or locks a system, demanding a ransom for data
                 recovery.  It  spreads  through  phishing  emails,  malicious  downloads,  or  security  vulnerabilities.  Once
                 infected, users lose access to their files until they pay the ransom, though payment does not guarantee


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