malware – Help! My PC at home has been infected by a virus! What do I do now?

I'm sorry to hear you have a computer virus. Fortunately, thousands of people face virus infections on a daily basis, and in most cases, the computer and all the data can be restored. Following a good online practice can prevent future infections.

There are two main approaches to eliminate a virus:

  • Use antivirus software to perform a "deep and clean scan".
  • Clean and reinstall The computer, known colloquially as "nuclear weapon from orbit."

The use of antivirus software is faster and easier, but there is a greater risk that the virus will remain silent and cause problems later on. It is recommended to clean and reinstall for knowledgeable users. It is usually possible to keep all your data while doing this.

Use of antivirus software

If you do not yet have antivirus software, there are several free options (for example, Windows Defender, AVG Free) and many payment options (for example, Symantec Endpoint Protection, Kaspersky Internet Security).

Make sure that the antivirus software is up to date.

Then you can run a full scan of your computer. Some AV software calls this a deep analysis. If a virus is found, you will have the option to quarantine the affected file.

Some advanced viruses have the ability to hide from antivirus software. To cope with this, some AV programs have the ability to "scan during boot." The AV runs before Windows starts, and in this mode, the virus is paralyzed, which allows the AV software to remove it more effectively. Once completed, you can start Windows as usual. Other AV software allows you to create a boot disk instead of "scan during startup".

The precise instructions for all this depend on your antivirus software. Consult the manual for more information.

Clean and reinstall

The basic idea is to copy all your data to an external hard drive and then reinstall Windows. This will give you a blank Windows installation, and we hope it is not infected. Then you must reinstall all software, restore all your data and customize the settings you had previously.

Before you begin, make sure you have installation media and license codes for all your commercial software. If necessary, you can extract a Windows and Office product key from your installation. You can also download images from Microsoft's disk, as long as you have a product key.

You must make a backup copy of all your data on an external hard drive. It can be difficult to get everything. People often forget their address book and bookmarks. This is a stressful point, because once you start reinstalling Windows, you lose the ability to recover more data. Alternatively, you can buy a new hard drive and place the old hard drive in a USB box like this one.

Next, you must reinstall Windows, all other programs, and then restore your data and settings.

Avoiding reinfection

You must follow the basic safety practices:

  • Keep all software updated. Secunia PSI helps you verify that the software is up to date.
  • Run antivirus software and keep it updated.
  • Enable the firewall (this is enabled by default in recent versions of Windows)

Beyond this, it is necessary to be careful. It is difficult to explain precisely how to do this, but here is a basic guide:

  • Be careful where you click.
  • Take special care when downloading software. Every exe The file that you download gets full access to your computer.
  • Be careful with removable media. Some viruses have executable files that look like folder icons. But if you click on them, you will be infected.
  • Be careful with shared drives, which can be on a NAS, or in cloud storage like DropBox.

Although your computer had a virus, it is possible that all your passwords have been captured. At least you should change your passwords for online accounts that are important to you, for example. Web mail, social networks, online banking. In general, it is not necessary to change low-value passwords for forums and e-commerce sites.

It is also possible that the credit card numbers have been compromised if you have used them on this computer. I think this is pretty weird, and changing your cards is a hassle (modest). Instead, keep your cards, pay attention to your statements and change the cards if fraud occurs.

If you have followed this to the end, well done! It is not an easy process, and hopefully you have recovered from the infection. Take care online, but do not be afraid of your computer.