How should you know your computer infected by virus?

How should you know your computer infected by virus?

Your computer system consists of thousands of files. There are few things as depressing as discovering that your computer has a virus and that you haven’t backed up all your treasured files and photos. All it takes is one wrong click or bad download.

Viruses are malicious software – known as malware – that can destroy files, steal personal information and damage your computer. Protecting your computer from dangerous malware with our checklist of symptoms and signs that show your computer has a virus.

So, here are the most visible signs or behavior that show your computer system has a virus -

Pop-up Hell

When you start your computer and find yourself faced with a barrage of pop-up ads, it’s safe to assume that you have a problem. Or multiple problems all popping up at once. Some websites will automatically generate pop-ups but you can block these via the settings on most browsers. However, if your computer is showing you with an endless supply of pop-ups when your browser isn’t open, it’s time to jump into action. This form of attack usually means that you’ve been infected by a type of Adware or Trojan tracker. One way Adware makes its creator money is by creating unwanted links to sites or throwing up windows to some pretty unsavory domains. You accidentally click the link and the hacker makes advertising money.

Slowing Down Computer Performance

If your computer system is taking longer than normal to start or programs are taking ages to open, it may indicate that the system is infected with a virus. If your computer’s performance is sluggish, check first that it isn’t due to a lack of RAM memory or hard disk space. If not, the reason may be a virus.

Lack of Storage Space

If you suddenly find yourself devoid of storage space on your hard drive, a virus may be doing its utmost to make your computer unusable.

Suspicious Hard Drive Activity

An excessively active hard disk where it makes continual noise or constantly spins – even though you’re not using your computer nor have any programs running – can be a sign your computer system is infected with a virus.

Missing or Extra Files

Keep track of the size of your hard drive. A virus may install copies of itself or unwanted files on your computer. Viruses also delete files unexpectedly. When you start seeing something strange or missing, it's time to run a virus scan.

Browser Woes

Your web browser becoming sluggish, your home page changing or being redirected to unusual websites are all warning signs of a computer virus infection.

Missing Files

Some malware cause problems by deleting files and programs or moving them around. Some may encrypt your files so you aren’t able to open them.

Infected Emails

If friends start receiving emails or instant messages from your social networks asking them to click on an attachment or link, it’s likely that a virus is attempting to spread to other computers via your accounts. If so, change your passwords immediately.

Sudden Freezes and Crashes

Because viruses damage your hard drive, they can cause your computer to experience a catastrophic failure. If you're lucky enough that your computer still turns on after a crash, make sure to run antivirus software to determine whether a virus was the cause.

High Network Activity

If your internet connection is very active even when you’re not using it, a virus may be busy sending information back and forth across the internet.

Security Attacks

Some viruses are designed to disable your computer’s protection. So, if you can’t open or install an antivirus program or your firewall, your computer may be infected.  

Crashes and Error Messages

If programs start opening and closing automatically, your system freezes or shuts down for no reason, or you see odd error messages, then you may have a virus infection.  Your computer knows something is wrong before you do. One of the most noticeable symptoms of a computer virus is the sudden appearance of pop-up messages warning you about missing system or application files. Research messages by putting them in a search engine to see if you can diagnose a virus.

Slower Internet and Processing

A slower Internet doesn't necessarily mean you have a virus, but if it's a sudden enough change in speed, it may be worth checking out. Use a speed test to check your internet speed and use your computer's task manager to measure processing power. If either seems slower than usual, perform a scan with your antivirus software.

Unexpected Ghost Behavior

Viruses can do all kinds of strange things to your computer. If your computer stops responding to clicks, decides to open files on its own, scrolls or acts as if a key been pressed when it hasn't, you may be experiencing computer virus symptoms. Your computer shouldn't seem like it's thinking for itself.

Outgoing Emails

Viruses try to spread themselves by email. If you notice emails in your sent box that you didn't send, you probably have a virus. If you get an email from a friend that seems suspicious, they might have a virus. Do not click on any links or open any attachments in questionable emails.


It's common to see ads as you browse the internet, but if you start seeing them when you're not actively browsing, that is a telltale sign of a virus. Do not click on these ads, even if they say they are for antivirus software.


Some of the viruses are so notorious that they become hard to detect. Install and run an antivirus software program to remove malware. Set the anti-virus software to automatically scan your system on a regular basis and protect your system against the most recent threats. And always make sure virus definitions are up-to-date and scan your system periodically (or whenever you have a suspicion).

If you know any other signs or behavior of virus that not mentioned in the above section, then please share your valuable experiences with us in the comment section. Let us together make the computer system more secure than ever and effective to use.

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