Do I have a virus?

A Windows PC often exhibits one or more of the following symptoms when infected with a virus or other malware.

These instructions assume you are running Windows. If you’re on another operating system, check the respective pages: Do I have a virus on MacDo I have a virus on AndroidDo I have a virus on iOS)

Programs slow down

Check out your computer’s task manager pressing CTRL+ALT+DEL to see if there are suspicious programs taking up excessive amounts of memory or processing power. If you are using a laptop, you can tell the processor is working hard if your fan is running faster and louder than usually. There are many legitimate reasons for a computer to slow down, so the slowness alone isn’t a dead giveaway of a malware infection.

Internet slows down

Use an online internet speed test to check whether your connection is slower on your computer than on your other devices when your computer is turned off. This might be a symptom of something malicious hogging your bandwidth.

Excessive freezing and crashing

Software crashes occasionally, that is just a fact of computing life. It is perfectly normal to have your computer bluescreen every now and then. Yet, if it happens extraordinarily often, it can be an indicator of malware messing your computer up.

Ads and popups

If you see ads and popups even when you’re not actively browsing, you very well might have adware. Adware is a type of malware designed to show you ads and thus get the malware creator ad revenue.

Browser acting up or changing the home page

Some malware installs unwanted toolbars on your browser or changes your home page. This is done to get the malware creator ad and referral revenue. At best, they are annoying and exist just to get referral revenue. At worst, they might be spying on your behavior and stealing your passwords.

Unwanted outgoing emails, Facebook messages or other automatically sent messages

It is in the nature of a virus to try and spread. Some viruses use emails or instant messages such as Facebook or Skype messages to infect new people. If your friends say you are sending them odd links, it is very likely that you are infected by malware.

Windows reports your protection is disabled even when you have a security suite 

Some malware tries to disable your protection to hide its presence. If your security suite should be working as intended and you still get these messages, it is a red flag. It might be a virus trying to cover its tracks. 

Emergence of never-before-seen files

Are there new files in system directories, or even your desktop directory that you have not seen before? Some malware leaves traces of itself on your computer when storing data. 

Windows appearing and vanishing immediately afterwards

Are you getting unexpected instances of odd windows popping up and vanishing? This might very well be a signal of malware making unauthorized moves on your computer.

If you suspect you have a virus or other malware, and you have an internet security suite such as F-Secure TOTAL, check that the software is up to date and run a full system scan on your computer.

If you don’t have an internet security suite, you can try F‑Secure Online Scanner, a web-based antivirus scanner designed to find and remove viruses, rootkits and other malware. Note that the Online Scanner is not a replacement for a full internet security suite and we recommend you try one out – there is a free trial for F‑Secure TOTAL available.

If you have a virus, refer to the instructions your security suite gives you or see the general malware removal instructions.

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