Is your computer hit by some kind of cyber virus? Have you found your computer frequently crashed down or run slower and slower? Wondering why your computer is acting so weird after you installed some free software? As a primary computer user, maybe you are feeling headache with the problem of your computer, but please don't worry because reading this article will help you understand virus better. A general instruction of cyber virus Virus is a computer program designed by intentional cyber hackers that can sneak into user's computer and infect other programs by modifying them in such a way as to include a copy of itself. It's a kind of code that damage or erase data, files, or software programs in your computer. Virus can reproduce and spread itself through Internet when users download infected file or click on malicious code on illegal sites or pages. Once the virus is embedded into your computer, it will immediately start to damage or destroy your system and mess up your computer. What's worse, it can be controlled by the hackers remotely so that it has the ability to steal your personal information or confidential data and then transfer them to the hackers behind for illegal purpose. The common categories of cyber viruses 1). Screen locking malware This kind of malware usually locks your computer immediately once they get in. What you see is that your computer screen has been totally occupied by a page pretending to be warning from local police department of government and with a scaring message stating your online activities have been detected as illegal movements thus you need to follow its instruction which guides you send a certain payment of fine by online transfer otherwise you will face a serious law issue then probably be put in jail really soon and your computer will continue to be locked until the payment is done. If you have been the one to believe this notice is from real government department and actually have paid the fine, I may say you have unfortunately became a fool to believe such a scam malware because this scaring message from so-called local department of police is definitely a scam aiming at robbing money as much as possible from timid people who has a guilty conscience. I bet you still can't get your computer unlock even you have paid the fine online. The most typical one is the Fake FBI virus which is rather popular all over the world recently, for more information about it please click here. Hackers created and updated them all the time to acquire their dirty money and achieve their immoral targets. 2). Trojan horse virus Trojan horse virus, usually is called Trojans for short, is defined as a type of virus that masquerades as a system file or helpful program with the purpose of granting a hacker unauthorized access to a computer. It's one kind of really tough and nasty virus that can cause critical damage to your computer. This kind of virus acts rather trickily in your computer and it's very difficult to be found out and removed from the system. One typical feature that departs it from normal computer virus is that Trojan virus does not attempt to inject themselves into other files like a computer virus. Trojan horses can make copies of themselves, steal information, or harm their host computer systems. Many Trojan viruses rely on drive-by downloads or install via online games or internet driven applications in order to reach target computers. Once your computer is infected by Trojan virus, it will attack your programs and files, block the internet visit, and make your system crash down. So this virus should be removed immediately before it wreaks chaos. Definitely it will bring nightmare to computer users who have unfortunately got this devil within their computers. 3). Fake antivirus This kind of virus is recognized as a horrible fake antivirus that pretends to scan your computer thoroughly acting like an authentic and powerful anti-virus software. Usually the interface of this fake program is just similar to the real anti-virus program. It aims at luring computer victims to purchase its full version which is definitely a scam. Once the fake program is installed, the virus can update itself and invade your computer deeply with other threats such as malware and spyware. After scanning, the rogue program displays that your computer maintains many virus infected items needed to be deleted soon. In fact, all fake security warnings are just false information that cheats unknown users for their money. The fake security program is a malware infection itself, so even the full edition of the fake program is never possible to detect and remove any type of computer viruses and other security threats. Don't ever trust such a fake security scanning program which is designed to attack your computer and violate your privacy aggressively. The virus can records your computer data and browser history to gather your precious information for remote hackers by design. In such an urgent situation, you need to uninstall such a nasty rogue program completely and promptly. Some tips to help you protect your computer from virus infection 1???Be cautious when clicking unknown links from sites that you are not familiar with because it can point your browser to download threats or visit malicious web site. 2???Do not download unknown free software or shareware that have not been widely proven to be trustful. 3???Avoid opening unknown attachments from spam emails because it may contain Trojan virus or other malicious programs. 4???Update your Windows system in time or else your system will be vulnerable. 5) Keep the firewall defender running so it can protect your system to some extent. 6) Make sure there is a password protecting your WIFI network which can help to avoid hacker's attack.