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How to Know if Your Computer Has a Virus

by Norton_Team

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.

Most people are willing to try everything up to and including an exorcism to get their machine back online. But are there ways to tell that your computer has been infected before it eats all your files? There are, as it so happens, and here’s what you can do about it. 

Pop-up hell

What to look out for: If 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.  

Source: Shutterstock

Some websites will automatically generate pop-ups but you can block these via the settings on most browsers. However, if your computer is bombarding 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 unsavoury domains. You accidentally click the link and the hacker makes advertising money.

What to do: This can be one of the more frustrating forms of infections but it can usually be sorted without too many problems. If you know the name of the Adware program in question, you can simply remove it by using the Uninstall option on your Control Panel. However, most infections won’t introduce themselves quite so obviously as Adware.

The best solution is to use a good malware removal tool to attack the malware and regain control of your computer. One advantage of the rise of Adware is the improvement in anti-Adware software to combat the threat. This will scan your system and delete any viruses. 

Someone hacks your account with a virus

What to look for: As the name suggests, viruses are mainly interested in spreading to as many devices as possible. A virus can infect your email or social media sites and the usual pattern is to try and infect as many of your friends or contacts as possible.

There will usually be some clues that this has happened. It may be your friends asking you why you’re posting weight loss advice on your social media accounts—something that will usually raise alarm bells, unless you happen to be a weight loss professional.

If you suspect there might be a problem, check the sent folder in your email and your social media timelines and see if there are posts or emails that you don’t remember sending. 

Sadly, we can’t blame all regrettable emails on viruses—but if you definitely don’t remember it and it looks like something you’d never send, you can blame a virus.

One of the worst case scenarios is that someone hacks your bank account. If random amounts are being withdrawn from your account without your knowledge, you can blame a hacker. 

Source: Shutterstock

What to do: People are pretty quick to spot a virus that has been sent from a friend’s account. Normally, you can expect someone to drop you a mail or contact you to warn you that your account is creating unwanted posts or mails.

The longer the hacker has control of your account, the more damage they can do. The first step is to get them out of the account by changing the password. This will prevent spambots from logging in, which means you’ll no longer be pestering your mates with diet pill advice.

A more dangerous scenario is if the account has been taken over by an actual person, in which case they could have changed your password, recovery address or security questions in order to lock you out. If you can reset the password, you’re not in too much trouble.

If you can’t reset the password, you’ll need to contact your email provider’s technical support or do the same with your social media account, which is probably going to be a fairly joyless experience.

The provider will doubtless look for proof that you are who you say you are so be prepared to dig out everything from proof of ID to your earliest childhood photographs.

(Yes, that latter one is a joke, but be prepared to have proof of your identity, address, and relevant personal details on you.)

If your bank account has been compromised, it’s best to call the customer card team or to pop into your local branch and sort it out at the source. Obviously, you need to do this as soon as possible unless you want to keep making donations to the Thieving Hackers Support Fund. 

You get locked out of your computer

What to look for: It’s a pretty obvious type of infection. Lock-screen viruses usually block all the controls on your device and generate an ominous screen message that claims to be from a law enforcement agency. Alternatively, less imaginative attackers will simply lock your screen with a blunter message that demands money.

This is a form of ransomware that tries to extort money from its victims by freezing their computer and demanding a payment in order to restore access. It’s a fairly evil form of virus that immediately attacks and encrypts your files to keep you from accessing them. 

Source: Christiaan Colen / Labelled for Reuse

What to do: Some ransomware can be removed by entering Windows Safe Mode and running a virus scanner or by using a System Restore to take your computer back to a point before it became infected.

If System Restore doesn’t work, you can run an offline virus scanner using anti-virus bootdisk software. If these options all fail, a factory restore could be your best option.

Getting your files back in one piece is not guaranteed. Sometimes you can easily regain access to your data but more serious forms of ransomware will actually encrypt your files—scrambling them so you can’t read or use them.

At this point, you’ll seriously regret not regularly backing your computer up!

Some victims have claimed that attackers have released the files when the requested ransom was paid but this is definitely not recommended. In fact, it’s up there with sending your bank details to foreign lottery scammers. You don’t know who they are or what they’ll do with your data or money. 

Malware that freezes, crashes or slows your device

What to look for: This can be a difficult type of infection to spot because it may be tricky to separate an infection from a simple dip in performance. If your computer dates back to 2001 or has a big square screen, the chances are that it’s just time to upgrade to something modern.

If your computer was operating at breakneck speeds and bounding through tasks before it suddenly experienced all sorts of performance issues, you might have a virus.

Some viruses can be a heavy drain on your computer’s resources and can lead to a serious dip in performance. Symptoms of an infection could be slow performance, a lag in response time or regular crashing or freezing. This is about as much fun as it sounds.

What to do: If your computer isn’t 10 years old and you’re pretty sure that it has a virus, the next step is to scan your computer for viruses using a good antivirus software. Delete any files that are flagged as suspicious and make sure to regularly scan for any signs of infection. 

Source: Shutterstock

It can be a particularly devious form of infection as the hacker may be using a keylogger to record your keystrokes, which would obviously steal all your passwords, PINs or any details you type.

What to do: The first step is figure out how the hacker is getting in. Otherwise, it’s the equivalent of trying to put out a fire in your kitchen while an arsonist is running around the other rooms with a can of petrol and some matches.

Finding the access point isn’t something most of us can do so ask a computer expert for help. It’s important to have up-to-date antivirus software to ensure that all traces of the virus has been scrubbed from your device too.

Once your machine has been secured and scrubbed, the next step is to change all of your passwords. This may result in a lot of forgotten or mistyped passwords over the coming weeks but at least you can rest easy once everything has been secured again.

If you’ve been unfortunate to be hit with a virus, we sympathise! 

This entry was posted on Tue Oct 27, 2015 filed under online security , online security tips and online threats

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