Sometimes computers can show symptoms of having malware or a virus. This can be in the form of running slow, weird popups, data being stolen, and many others.
In this post we will talk about identifying the signs and symptoms of malicious software, and what to do about it if you suspect there is an issue.
Most common Symptoms
Some malware or viruses may not be immediately obvious, but some others can be pretty easy to recognize.
There is also some software that can be bypassed by certain anti-viruses because they aren’t’ inherently malicious themselves. Even though that’s the case they although they often lead you down malicious paths.
The most common symptoms are:
- Sudden slowdowns – Your computer boots and processes everything slower. This is especially concerning if the computer was fast before this.
- High CPU, RAM, or disk usage – High fan usage, excess heat, unknown programs using a lot of power. This can be tracked in the Task Manager.
- Frequent pop-ups – Ads appear even when you’re not browsing, or you get fake security warnings claiming your PC is infected. Keep in mind this is sometimes not malware or a virus and just an accidental configuration of notifications.
- Browser changes – Your homepage, default search engine, or new-tab page changes without your permission. You may also notice unwanted toolbars or extensions. These are often called Browser Hijackers.
- Random New Programs – New applications that appear that you didn’t install.
- Crashes or instability – Apps freeze, Windows Crash/Bluescreen, Frequent Restarts.
- Security software problems – Your antivirus is disabled, won’t update, or you can’t access security-related websites.
- Unusual network activity – Slow internet connection when it was otherwise fast before.
- Emails or messages sent from your accounts – Friends report receiving spam, links, or strange messages from you that you didn’t send.
- Files disappearing or changing – Documents become corrupted, renamed, encrypted, or inaccessible. This can be a sign of ransomware which can be one of the most devastating virus types.
- Login problems – Passwords failing, activity notices that aren’t you.
- Webcam or microphone activity – Indicators of use turn on without you actually using them, though can often be caused by something else that uses the respective device.
Windows Security (Windows Defender)
Windows Defender is a built-in antivirus software on a Windows 11.
Scanning with antivirus software will help you find out if you have a virus. This can be done through third party apps or Windows Defender.
To find these built in security options, type “Windows Security” in the search bar located on the taskbar next to the start button.
Select the “best match” shortcut to open it. You can also head to Settings > Update & Security > Windows Security > Open Windows Security or select the shield icon from the tray located on the taskbar.
This will open Windows Defender, where you will see options such as Virus and Threat Protection.
You will also see when it last scanned and it will give you an option to scan again.
Although Windows Defender is solid, it can still miss certain things, especially borderline programs.
This is where Malwarebytes comes into play.
Malwarebytes
Sometimes things can get past Microsoft Defender, especially programs that aren’t necessarily malicious in nature but can lead you down a bad path. This includes things like Toolbars, bowser hijackers and other forms of Adware.
Malwarebytes is free antivirus software that we recommend running if ever you suspect malware or a virus.
Go to malwarebytes.com to download the version for your specific computer/OS.
Choose the Free Download button to use this as a one-time checkup.
Once it is downloaded, run the software.
Once open you can choose to do a regular scan of the computer.
If you truly want to be as thorough as possible you should hit the dots next to the scan button, and choose deep scan.
This will look for any files hidden deep within the system, but can take a long time. Although it can be time consuming it is highly recommended. Especially if a virus is suspected.
Once it finds something suspect, it will count files associated with it as a detection. Each file = 1 detection.
Once the scan is complete you will have the option to quarantine the bad files, and then deleted them entirely from there.
Checking the task manager
Another thing to do to see if you have a virus running on your computer is to check Task Manager.
Press Ctrl+Shift+Esc to open the Task Manager. What you will see is a list of every process currently active on the computer.
You will see a lot of processes here you likely won’t understand. A lot can be legitimate or integral to things running smoothly, but if you see one that seems off or is using a lot of processing power, you should Google it or ask an AI for more information about it.
To stop a process from running, single click on the name and click the “end task” button or right click on the task and select “end task.”
If it is indeed a malicious process, we need to narrow down where it is coming from, whether in a folder somewhere or tied to a program that must deleted.
Bottom line
Although these programs are pretty good, you can’t always be fully sure if you got rid of what is causing issues, or if something is still lurking in the system.
Anti-Virus/Malware programs run off of libraries of virus definitions that they search for. As they add these definitions hackers will find ways to counter them which creates new files that need to be detected and added to library of definitions. With current technology it is a constant war of back and forth counterplay.
If you truly want to be sure there is nothing on the system it is recommended to back up all important files and fully reinstall Windows after scrubbing the disk clean.
For more official information, check out this Microsoft page about Windows Defender.
We have another version of this post for people who are using Windows 10, which is linked here.
If you have specific questions about security on Windows 11, or if our terminology isn’t clear, please use our contact form to send us a message, or give us a call and make an appointment.
