I think my computer has a Virus - Whats the difference between computer threats?

Malware, short for malicious software, is any software used to disrupt computer operation, gather sensitive information, or gain access to private computer systems. It can appear in the form of executable code, scripts, active content, and other software. Malware' is a general term used to refer to a variety of forms of hostile or intrusive software. Malware includes computer viruses, worms, trojan horses, ransomware, spyware, adware, scareware, and other malicious programs. As of 2011 the majority of active malware threats were worms or trojans rather than viruses.


Computer Virus - A computer virus is a malware program that, when executed, replicates by inserting copies of itself (possibly modified) into other computer programs, data files, or the boot sector of the hard drive; when this replication succeeds, the affected areas are then said to be "infected".

Trojan horse - A Trojan horse, or Trojan, in computing is a generally non-self-replicating type of malware program containing malicious code that, when executed, carries out actions determined by the nature of the Trojan, typically causing loss or theft of data, and possible system harm.

Spyware - Spyware is software that aids in gathering information about a person or organization without their knowledge and that may send such information to another entity without the consumer's consent, or that asserts control over a computer without the consumer's knowledge.

Adware - Adware, or advertising-supported software, is any software package which automatically renders advertisements in order to generate revenue for its author.

Computer Worm - A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers.^[1] Often, it uses a computer networkto spread itself, relying on security failures on the target computer to access it. Unlike a computer virus, it does not need to attach itself to an existing program.

Ransomware - Ransomware is a type of malware which restricts access to the computer system that it infects, and demands a ransom paid to the creator(s) of the malware in order for the restriction to be removed. 

Scareware - Scareware, included into the class of malware known as Rogueware, comprises several classes of ransomware or scam software with malicious payloads, usually of limited or no benefit, that are sold to consumers via certain unethical marketing practices. The selling approach uses social engineering to cause shock, anxiety, or the perception of a threat, generally directed at an unsuspecting user. Some forms of spyware andadware also use scareware tactics.