More and more types of computer viruses, not all computer viruses are complex. Virus means to bring and give bad impact. Viruses will multiply to fill the hard disk memory and make the ram becomes smaller. Not only that, if the virus is allowed to continue in the computer system, it will damage the entire system and device. To find out the signs your computer is attacked by a virus and
1. Antivirus is not active

When a virus is about to attack your computer or laptop, several types of this virus or malware can disable the antivirus that you installed on your computer. Thus, the malware can enter freely into the computer. For this reason, you should act immediately when the antivirus cannot be updated or is inactive. There may be a virus or malware that enters the laptop or computer device.
2. Slow Computer or Laptop Performance
There are many reasons why your laptop’s performance is slow, one of which is a virus or malware. Slow computer performance is usually because the malware or virus is running applications or services in the background without your knowledge.
3. Your Files Are Lost or Locked

The most common cyber crime is ransomware attacks. The way ransomware works is to lock files or data on the victim’s device and then ask for a ransom if the data can be unlocked again. Some ways that can be done to anticipate is to back up important files regularly and not have to pay the ransom demanded by hackers.
4. Difficult to Connect to the Internet
Slow internet network is certainly a common thing. But it’s different if this happens suddenly, this could be a symptom of a device infected with a virus or malware. Although, some types of malware often change network settings to add proxies and block access to the internet. This is done to avoid attempts by device owners to download antivirus. One way to do this is to download an anti-malware tool like Malware bytes on another computer and then transfer it to the infected computer via USB.
5. Storage Space Suddenly Full

Storage space that is suddenly full can also be a sign that your computer is infected with malware or viruses. For example, yesterday on your laptop there was still space of 30 percent of the total memory, but today there is only less than 5 percent of free space. You’re actually not downloading anything at all. The only plausible reason is that malware is silently downloading files or installing programs in storage space.
If you already have these signs on your computer or laptop, of course there are things you can do to avoid viruses or malware on your computer
1. Enter Safe Mode

Before running the program, you must disconnect from the internet, and do not turn it on until you have finished cleaning the computer. This can help prevent the spread of malware. If you think your computer is infected with malware, turn your computer into Safe Mode. In this mode only small programs and services are needed.
2. Delete temporary files
Still in Safe Mode. Before you scan your computer with an antivirus, it is recommended to delete temporary files or junk files that have been used. This method speeds up the virus scan process, frees up storage and may remove the malware. To use the Disk Cleanup tool, just type Disk Cleanup in the search box in the Windows Start menu. Or if you have CCleaner it can be used, because its function is the same as Disk Cleanup.
3. Download malware scanners

If you already have antivirus software, you should try another antivirus program, because maybe your antivirus doesn’t detect the malware, because no antivirus can detect all viruses or malware from a million types of viruses. There is one Malware Scanner that can be considered powerful enough to clean malware viruses, namely Malware bytes. Performing a virus scan on a computer that is not infected with a virus can also be done regularly at least once every 2 months so that the condition of the PC remains healthy and free from malicious viruses.