Computer viruses are programs / applications that can replicate themselves and spread by inserting themselves in programs and other data. usually the user does not know if the computer in his possession is infected with a virus until one of the data is lost or the program on the computer cannot be run.
Computer viruses are generally made for purposes that are not good, many negative effects caused by computer viruses such as multiplying themselves so that memory becomes small, this makes the computer often hangs or freezes, then changes the extensions on files and programs that make programs / files it cannot be used, and can also steal someone's personal data without the person's knowledge. besides that, viruses can damage the hardware on the computer.
In fact nearly 95% of viruses attack users of the Windows operating system. The rest attack Linux / GNU, Mac, FreeBSD, OS / 2 IBM, and Sun Operating System.
Types of viruses on a computer
Worm - Duplicate itself on the hard disk. This makes computer resources (hard disks) full of the worm.
Trojan - Retrieves data on infected computers and sends them to the trojan maker itself.
Backdoor - Almost the same as a trojan. However, the Backdoor usually resembles a fine file. For example the game.
Spyware - Virus that monitors infected computers.
Rogue - a program that mimics an antivirus program and displays activity like a normal antivirus, and provides false warnings about a virus. The goal is for users to buy and activate the fake antivirus program and bring money to the makers of the rogue virus. Also rogue can open security holes in computers to bring in other viruses. Rootkits - Viruses that work like ordinary computer systems.
Polymorphic virus - A virus that likes to change so that it cannot be detected.
Metamorphic virus - A virus that changes its own coding to make it harder to detect.
Cellphone viruses - Viruses that run on cell phones, and can cause a variety of effects, ranging from damaging cell phones, stealing data on cell phones, to making calls silently and spending credit on cell phone users.
There are so many viruses that have spread and it is very difficult to stop the spread, but we can do a number of ways to avoid contracting the virus on the computer, one of which is like the post I made before
- Simple trick to protect Computers and Flashdisk from autorun.inf virus
besides that we can also use antivirus that can detect the presence of viruses on the computer. So that the data and programs become safe.