Malware is the general term used for any program which is intended to do harm to a computer and its owner. Some can corrupt and delete your files while others can lower your PC’s performance. Some can steal files, histories and important information from the user.
          

A computer virus is one of the most popular malicious software (thus, mal-ware). It works by attaching itself to a program file. When the program is executed, the virus code allows it to infect other files—including network connected computers.
          

Another malware is the worm. Unlike viruses, worms do not need execution of program files. They infect computers by actively moving in the network. Trojan horses, on the other hand, pretend to be ordinary harmless programs. But when installed, they can damage your programs and delete your files.
           

Next in the list are spyware. It is intended for monitoring the web activity of the target. Initially made for marketing purposes, spyware can also be used to steal important data like PINs and passwords.
Scan, scan and scan
           

Now that the members of bad-ware are known, you must know one of the best ways to fight them: scanning with an antivirus or antimalware. You can use free antimalware but read reviews first (Be sure they are not Trojans). It is advisable to purchase a licensed antimalware, which includes full internet solutions.
           

These “good-ware” will act as your safety wall for every file that will enter your computer—through the web, network or through portable storage. Scan every executable file or drives, especially if they were used in public computers. Scan emails and office documents because malware can use Java and macros.

Use network protection
Most Operating Systems (OS) have built-in firewall. This feature prevents unauthorized network usage by programs (both incoming and outgoing). Firewalls are often enhanced with antivirus or antimalware tools.
          

With network protection, worms “lurking” in the Local Area are prevented from entering your PC. Network-hopping viruses are also blocked from copying themselves to your drives.
           

New OS have enhanced network security. This includes username and password input for a computer to access another. Reading and writing permission on drives can also be changed. This can prevent automated access of programs; thus, containing the malware and the potential damage.

Install genuine, unaltered software
The word “free,” when beside a downloadable program, may sound good. But it may serve as a warning too. It is best to download software from the maker’s official site and from authorized mirrors. Hack-forum posted links and peer-to-peer (P2P) networks are dangerous places to collect programs.
          

It is smart to read reviews and discussions regarding the software before download. If several references agree with its safety, then it must be OK to use it. If unsure, it is best to consult IT-adept friends or technicians first.

One must also be careful with the browser and browser tools that they use. Certain toolbars are actually adware and spyware. Some malware pretend as download managers and search bars. Symptoms include pop-up advertisements and, occasionally, sudden appearances of obscene Flash-based ads. Use a trusted browser and be selective on installing add-ons.