These are destructive software or malicious one which exists in the form of computer virus, computer worm, trojan or trojan horse which may get attached to email or gets in a file while downloading from a website or via compact discs. In the world of cyber era these software are highly dangerous. The types of Malware are as follows:
- Computer Virus: It is a malicious programme which is written with the intention of slowing down the system operation or to delete the file. The reason they are called virus because they are easily spreads to other machines to which the communicate.
- Computer worm: It is a self-replicating malicious programme i.e. it multiplies on its own, such that it keeps on creating up its copies and eats up entire disc space or memory. It is self installing, harder to detect and it tries to erase or steal the data from the hard disk. It is more dangerous than virus. Eg ILOVEYOU ,MSBlast etc.
- Trojan/Trojan horse: It is a malicious programme that comes to the system disguised as the useful application programme and when it is opened the Trojan starts executing and tries to destroy the file.
- Adware: It is an advertising supported software. It is any software application in which advertisement banners are displayed while the programme is running. It generate the revenue by delivering the Add.
- Spyware: It is a computer software installed secretely on a Computer through a users internet connection that secretly monitors users behaviour and transmits information gathered from the computer back to the unethical hacker.
- Ransomware: It is a subset of malware in which the data on victims computer is locked , typically by encryption and payment is demanded before the ransom data is decrypted and access return to the victim.