What is AntiVirus Software?

Common types of Malware threats are:

• Spyware
  Software that lurks in the background on your computer and keeps track of what you are doing.  Usually used to gain access to things like your online banking information, etc.
• Virus
  A computer virus acts just like one in your body.  It can spread throughout your computer, rendering it very slow or completely disabling it.
• Trojan
  A Trojan virus can be very difficult to detect and protect against and is probably the most common threat online today.  Trojans usually come from visiting infected websites or come via email.
• Ransomware
  This form of malware will lock down your computer, usually making it unusable until you pay the author of the virus some kind of fee.
• Adware
  Adware is one of the least destructive of all the forms of malware but unfortunately is one of the most common.  Adware works by infecting your computer and typically redirecting your web searches to another page where the author of the malware will get some kind of compensation for your clicks.
• Botnet
  A botnet is a form of virus that works by connecting many infected computers together in a hidden network.  The network is controlled by the author to do things like perform DDOS attacks.

There are even more forms of malware but these are the most common ones and likely ones that might infect you.