1- What is a computer virus:
A computer virus is a software program that can replicate and spread from one infected computer to another. Infected objects can be system, program, or document files. After infecting your computer, it can slow it down, damage the contents of infected files, lose data, or affect the normal operation of your computer system.
The virus can also use your computer to spread illegal advertisements and send spam emails that exploit security (adWare), steal your personal information such as bank account number, credit card number, etc. (spyware). Some types of viruses can use your computer to create a botnet (virtual computer network) to attack other server systems and websites, etc.
2- Type of virus on Windows-based computers:
There are a number of computer viruses that can prevent your computer from working. Here are some of the different types of viruses:
Trojan horse: It is an email virus created by an email attachment. If it opens, you can save your hard drive for any personal and financial information, such as your social security number, account, and PIN. Once your information has been collected, it is sent over the Internet to a hacker or thief.
Macro Virus: It is a computer virus that infects documents in Visual Basic language for applications such as Microsoft Word, Microsoft Excel, etc. This type of virus can cause damage (such as deleting data from the hard drive, for example).
Worms: It is a program that has the ability to self-replicate. It can move from one computer to another and replicate on your computer system and then spread hundreds of its copies to other computers that could cause widespread damage.
Rootkit Virus: It is a program that can cover the processes, files and data in the computer’s Registry (a database used to store Windows system and program settings). Rootkit is generally used to hide the activities of viruses and processes that harm your computer. It is to help a hacker control the system.
Bootsector Virus – A virus that attaches itself to the first part of the hard drive that is read by the computer at startup. They are usually spread via floppy disks.
Logic Bombs: It is a program that is used to send a lot of data to the same email address and saturate the system or block the server connection. It is also used to threaten others (for example, mail bomb, etc.).
Memory Resident Virus: This type of virus lives in RAM memory. From there you can override and interrupt the operations executed by the system. It can corrupt files and programs that are opened, closed, copied, renamed, etc.
Multipartite viruses: These viruses spread in multiple ways. It can vary in its action depending on where it is installed and the presence of certain files.
3- How to contract a virus and Prevention:
Here are 3 common ways your computer can become infected with viruses:
Email: You receive an email from a person that contains one or more viruses. If the attached file is opened, viruses can infect files on the computer. Viruses can also send emails to people from your email address book or email folders automatically. Therefore, you should not open unknown email attachments or run a virus scan after opening them.
Internet: If you download an exe file or data file from the Internet or other network shares, viruses may be transferred to your computer. Free software programs on the Internet sometimes contain viruses, especially if they are downloaded from sources such as torrents or Usenet newsgroups. Therefore, if necessary, you should download files from trusted resources.
Peripheral Devices: Devices such as MP3 player, USB flash drive, memory card or CD Rom are also means of spreading viruses. Therefore, remember to run a virus scan for them after they are connected to your computer.
4- Virus infection symptoms:
These are some of the symptoms that may indicate virus activity:
• Your computer has unusual activity (for example, programs crash a lot or run slowly).
• Messages or pictures (not related to your current task) appear unexpectedly.
• A program may start unexpectedly.
• Your firewall reports that a certain application is trying to connect to the Internet (unrelated to what you are working on).
• Your friends say they get emails from you but you didn’t send them any.
• You get a lot of system error announcements. (Note: this can also come from other activity, such as a hardware problem or a genuine system error)
• Windows does not run when you turn on your computer. (Note: this can also be caused by a hard drive issue)
• You notice that folders and files are being deleted or modified.
• You find that there is access to your hard drive (one of the small lights is blinking) even though there are no programs running.
• Your web browser has abnormal prompts, for example, you open an unknown web page or you cannot close browser tabs.
• Advertising pages appear, change the desktop wallpaper.
• The exe files occur and have the same names as the folders.
• In the right corner of your computer, there is a small symbol written “Your computer is infected” or “Virus alert”, etc.
• When you open a USB flash drive, unknown files such as Autorun.inf, New Folder.exe, etc. may appear. appear.
• You cannot press Control + Alt + Delete (Task Manager) and you are warned that the administrator prohibited it.
• The folder options disappear.
• Your computer keeps rebooting when you try to shut it down.
• You cannot sign in to your Windows account with the correct sign-in details.
5- What to do when infected:
• Make sure your antivirus software has the latest update. If necessary, download the update from another computer and update it manually.
• Disconnect from the Internet or local area network (LAN).
• If Windows is not running, start it in Safe Mode (when you turn on your computer, keep pressing F8 as soon as the computer starts running, then choose ‘Safe Mode’ from the Menu).
• Run a full virus scan.
• If your computer is heavily infected but has important files or documents on it, run a full scan with your up-to-date antivirus software. If you find viruses, remove them all, then open each auxiliary drive (USB, USB stick, etc.) and find the Autorun.inf files and remove them. Then restart your computer.
• If you have any difficulty finding a way to remove faulty programs, consult your Internet security software provider for a dedicated tool essential to remove them.
• If you find a faulty program, follow the instructions of your Internet security software provider. Good security software will provide options like disabling infected files, isolating possibly infected files, removing worms and trojans.
• If you don’t have any important files on your computer’s drives, format the drive, and then reinstall Windows and applications. This is quite an extreme and lengthy process and it is recommended to back up your computer’s settings before beginning. When you’re done, don’t open any auxiliary disks (USB, USB thumb drives, etc.), install antivirus software, run a full scan, look for the Autorun.inf files, and delete them. Reboot your computer after that.
• If the Anti-Virus software finds nothing, your computer may not be infected. Verify that your hardware and software that is installed on your computer comply with the hardware specifications of the Operating System. Remove unnecessary or unwanted programs to save resources, and make sure you have updated your Windows operating system through Windows Update.
