Virus, trojan, spyware, and adware have always been threats to computers regardless how better antivirus software has become. Sometimes it takes as little as 2 seconds for your computer to be infected by virus. You may have visited a wrong website, downloaded a wrong piece of software, opened an unexpected email attachment, or maybe your friend has just shared a virus-infected file with you without even knowing that the file carries virus.
Most viruses target Windows computers. Since Apple Mac computers have become much more popular, virus makers have started targeting Mac OS.
Destructive viruses can cause data file corruption, file damage and system failure. Some world famous viruses are known to have crashed millions of computers, or stealing confidential information from users. Trojan horses open certain ports and leave the computer potentially vulnerable to other attacks. Virus is infectious from one computer to another through exchange of file or email. Spyware, adware tracks user Internet surfing behavior and deliver buyer specific marketing materials. The most common form of such materials are pop-up advertisements. Browser hijack is a common symptom of spyware and adware, it takes over your computer Internet browser and sets your homepage to an unfamiliar search page, delivers popup ads randomly, or shows you some “prizes” that you have “won”.
Removing virus, trojan, spyware and adware is usually time-consuming and not an easy job. It’s far beyond knowledge of normal computer users. It may also result in loss of data if not done correctly. Installing antivirus software after virus has already got into your computer usually will not help. Many viruses are capable of hiding themselves from antivirus programs and even disabling them.