Malware (malicious) is software program that will enter into any computer or a network without the computer owner's awareness. A malicious program can be of anything like a virus, spyware, worm, Trojan or some unwanted software. Shaoxing, China is the malware capital according to Symantec. Most of the malware are to execute at a particular time and it will damage many computer before anyone get noticed.
Protect your computer with some antivirus software which supports malware protection