Annoying pop-ups regularly appear on your computer screen. Your online bank account has been “hacked” by an unknown person. Your computer crashes or freezes for no reason at all. Your computer shuts down automatically. You see a blue screen in your monitor again. Your computer is running much slower than usual. You are getting “returned mail” messages from your inbox even if you didn’t send those emails. Your computer seems to have a mind of its own.

Chances are, your computer has been attacked by a certain type of malware. Malware is a mix of the words “malicious” and “software”. It is used to refer to any computer program intended to intrude, annoy or attack your computer system without your knowledge and consent.

These following are common types of malware that you would most likely encounter if your computer is connected to a network. These terms are often used interchangeably to describe any malicious software that infiltrates computer systems and causes a substantial amount of damage. To put it simply, these are things that you don’t want to have inside you computer.

Virus

A virus is a self-replicating computer program that attaches itself to a file in the computer, thereby corrupting it. This potentially harmful form of malware can infect one computer after another when it is sent over a network or transferred via removable media such as CDs, hard disks, and USB drives. Viruses can be disguised as attachments of image, audio and video files. The word “virus” is often inaccurately used as a general term for all types of malware, even those that cannot replicate themselves.

Worm

A computer worm is a type of malware which can also replicate and send copies of itself to other computers. Most worms are created to eat up network bandwidth and disk space while some are created to really destroy. Worms and viruses can cause serious damage by attacking essential system resources, eventually causing your computer to crash– or freeze at the very least.

Trojan Horse

Just like the horse figure that allowed the Greek attackers to infiltrate the city of Troy without being seen, this form of malware also deceives by appearing like harmless software to unknowing users while sneaking a potentially harmful package into their computer system. Free software like screensavers, games or anti-virus software (ironically) that you can easily download from the internet are the most common vehicles for Trojans to invade your computer.

Trojan Horse

Spyware

A spyware is a malicious software installed to a computer to secretly gather information and monitor its users. That being said, spyware programs can collect your personal information and internet surfing patterns without you knowing it. They can also take over your computer by installing unwanted programs, changing some of your computer settings or redirecting your web browser to another page.

Adware

Adware is a shortcut for advertising-supported software. It is a software package that plays automatically or downloads product advertisements to your computer after installing the software bundled with it. These advertisements sometimes interrupts your work by popping up on the screen while you are using an application. Product manufacturers often use this adware to encourage users to buy a “licensed” copy of the product so they could get rid of the advertisements.

Crimeware

Crimeware is a more sophisticated type of malware that is specifically designed for financial crimes and identity theft. It is used by cyber criminals to access online financial accounts and complete unauthorized transaction all for the purpose of extracting funds from companies or individuals that transact their business online.

A crimeware can secretly install a hardware or software which takes note of the keys struck by the user on the keyboard, thus, enabling the criminal to collect sensitive information like passwords, usernames or even credit card numbers.

Anti-Malware

The best way to prevent malicious software from attacking your PC is to install anti-malware products in your computer before connecting it to a computer network or the internet. This may cost you a bit more than just downloading a free anti-malware from unknown sources but it will definitely help you sleep better at night. It is also a good idea to update them on a regular basis. After all, an ounce of prevention is always better than a pound of cure.