Degraded computer performance including crashing apps, frozen screens, slow loading websites, strange processes running in the background, and high CPU usage are often signs that your computer has been infected with a virus or other malware.  But with modern malware that’s not always the case.  A computer will slow down dramatically for many reasons, including memory leaks, hungry apps, and runaway processes using excessive system resources.  So first of all, just give your computer a quick reboot if something is not working properly.  This will fix many technical issues and should always be attempted first before worrying about malware or trying to manually troubleshoot computer issues.


While a slow or misbehaving computer is still a tell-tale sign you have malware, modern malware is far more likely to lurk silently in the background, designed to evade detection as it harvests your passwords, credit card numbers, and other personal information.  Decades ago, computer viruses were designed to be noisy and use massive amounts of system resources.  However, modern malware is much more sophisticated and is now used by cybercriminals to make money.  Today, advanced malware will rarely cause any noticeable problems on compromised endpoints.


Therefore, the best way to detect whether or not your computer has a malware infection is to regularly scan your computer for malware with high quality antivirus software.  Also, Windows Task Manager is an excellent and perhaps underutilized tool and should be checked periodically for unusual processes with special attention paid to any processes using a large amount of CPU, memory, or disk resources.


If you come across a suspicious or unusual process, you can right-click on the process in Task Manager for more options.  You can begin investigating any process by selecting “Search Online” to learn more about a specific process running on your computer at any given time.  But even seasoned cybersecurity professionals can be fooled by a malicious process masquerading as a legitimate one, so again the best option is to scan your computer for malware regularly even if it’s performing well.  


The good news is Windows 10 and 11 automatically scans your computer for malware with Microsoft Defender, its native security app.  Of course, you can also initiate a scan manually by opening Windows Security through the Settings app.  Click “Quick Scan” to scan your system for malware.  If malware is detected, Microsoft Defender will provide the option to remove it automatically.  In addition, it’s a good idea to scan your computer with different antivirus scanners as well.  There are many high quality free scanning antivirus products available so you can try to catch any malware that your primary antivirus may have missed.  Some of the best malware scanning and removal software include MalwareBytes, Bitdefender, Adaware, Norton, TrendMicro, SUPERAntiSpyware, and Avast.  You can use the free version of many of these premium antivirus and anti-malware products to scan your computer for hidden malware and remain confident that your computer is protected and in good health.