Computer virus typesA list of well-known computer virus types:

Memory Resident Virus (2) - stays in memory after it executes and after its host program is terminated. In contrast, non-memory-resident viruses only are activated when an infected application runs.Overwriting Virus (3) - will copy its own code over the host computer system's file data, which destroys the original program.Direct Action Virus (4) - is considered to be “non-resident” and functions by selecting one or more files to infect each time the code is executed. The primary intentions of this virus is copying itself and to spread infection whenever the code is executed.Boot Sector Virus (5) - infects computer systems by copying code either to the boot sector on a floppy disk or the partition table on a hard drive. During startup, the virus is loaded into memory. Once in memory, the virus will infect any non-infected disks accessed by the system.Cluster Virus (6) - associates itself with the execution of programs by modifying directory table entries to ensure the virus itself will start when any program on the computer system is started. If infected by this virus it will look like every program on your PC is infected; however, this virus is only in one place on the system.Macro Virus (7) - is written in a macro language and infects Microsoft Word or similar applications (e.g., word processors and spreadsheet applications) and causes a sequence of actions to be performed automatically when the application is started or something else triggers it.Computer virus symptoms (signs)A few computer virus symptoms are:

Computer and/or internet suddenly slowerComputer behaves weirdPC freezes and crashes a lotUnusual error messages appearFiles have been automatically deleted or addedUnwanted advertisements appearEmails have been sent from your account to your contacts (which you know you didn't sent)Sudden hardware problems (e.g., display acting weird)Antivirus software and/or its shields are turned off automaticallyPC automatically restarts (reboots) by itselfComputer virus prevention tipsKeep your operating system and software always up-to-dateUse a firewallUse antivirus softwareDon't ignore security warnings from Windows or your antivirus softwareDon't install and use pirated softwareIf you don't use Java, then remove or disable itDon't click on OK, Yes or Run when a pop-up window appears and ask you to install unknown software. Here's one example: “Your windows computer could be at risk! Install this repair tool to protect and clean your system by clicking Secure Now as soon as possible” Don't fall for this trick!Before you want to install free software (freeware) first check if its reliable by reading reviews about itAlways download software from the official link or from a trusted websiteDon't click on a link (in emails or web pages) if you don't trust it.Use a secure and safe web browser like Google Chrome or Mozilla Firefox and keep it updatedWhen installing software, always pay attention and always read everything clearly before clicking Next, OK, Install, Continue, etc.Microsoft recommends that you disable SMB1 on Windows for security reasons.trick to install a computer virus on your computer Computer virus protectionThe BEST protection against computer viruses is YOU.

Look:

You can have the best protection there is, but even the best antivirus software can fail to detect new malware (e.g., computerviruses, ransomware, spyware, etc.). (8)

Malware threats grow so fast, that antivirus programs take too long to catch up with malware (even the best free or paid ones). (9)

Therefore, the best protection is yourself.

If you do any of the following:

Ignore Windows and software updatesDon't use antivirus softwareUse pirated softwareInstall free software without checking if it's reliableClick on every link you seeIgnore security warnings from Windows or antivirus softwareClick on buttons in pop-up windows that appearThen there's a good chance that your PC will get infected one day.