Malware is short for 'malicious software'- computer programs designed to infiltrate and damage computers without the user's consent."Malware' is the general term covering all the diferent types of threats to your computer safety such as viruses,spyware,trojans,worms,rootkits and so on.
TYPES OF MALWARE
Virus is a program or software.A computer virus is a type of malicious software that,when executed,replicates itself by modifying other computer programs and inserting its own code.When this replication succeeds,the affected areas are then said to be 'infected' with a computer virus.VIRUS satnds for - Viatl Information Resources Under Seize.
A worm is a self replicating and self spreading malware.It is a program that spreads copies of itself through a network.A worm operates through networks,and a virus can spread through any medium.The worm spreads copies of itself as a stand-alone program where as the virus spreads copies of itself as a program that attaches to or embeds in other programs.
A botnet is a network of infected computers,where the network is used by the malware to spread.It is a collection of compromised computers often referred to as 'zombies' infected with malware that allows an attacker to control them.A botnet can be used to perform various attacks,eg: flooding targeted networks and devices with too much traffic and stealing data from hosts infected with the bots.
Ransomware is a form of malware that essentially holds a computer system captive while demanding a ransom.The malware restricts user access to the computer either by encrypting files on the hard drive or locking down the system and displaying messages that are intended to force the user to pay the malware creator to remove the restrictions and regain access to their computer.
A rootkit is a type of malicious software designed to remotely access or control a computer without being detected by users or security programs.With rootkit,it is possible to remotely execute files,access /steal information,modify system configurations,alter software,or install malware.Rootkits hide its presence.