No one wants their PC to get infected with malware, but there’s always a slight risk of it happening. If your PC has been infected with malware, the first advice is not to panic, as that’ll lead to hasty decisions that cause more damage.
The first course of action is to observe what kind of malware has entered your PC, its effects, and its origin. For example, it could be from a file downloaded online, or a hard drive you previously inserted into your PC.
After identifying the malware and its effects, you can take delicate steps to fix your PC using malware removal tools to recover all possible data.
You’re at the right place if you’re facing this issue, as I’ve created this guide to explore the practical steps to fix a malware-infected PC. Read on, and let’s get your PC fixed.
Steps to fix a malware-infected PC
Disconnect from the internet
Malicious actors often design malware to send sensitive data from infected PCs to their online servers, so you should begin by disconnecting from the internet.
You might not be sure if the malware is actually sending data, but it’s better to be safe than sorry. Disconnecting from the web prevents any sensitive data from being extracted from your PC. It also prevents the malware from infecting any other PC connected to your network.
Restart your PC in ‘Safe Mode’
After disconnecting from the internet, the next step is restarting your PC in “Safe Mode.” Safe Mode is a diagnostic mode that starts your PC with only the essential, pre-installed apps running. It disables the function of all third-party apps, including the one that was infected with malware, preventing further damage.
To enter Safe Mode on a Windows PC, follow these steps:
- First, restart your PC normally.
- In the Sign In menu after a normal restart, hold your Shift key and click Power > Restart.
- Your computer will restart and show the Choose an Option screen. Click Troubleshoot > Advanced Options > Startup Settings > Restart.
- After the computer restarts again, press 4 or F4 to start it in Safe Mode.
For macOS PCs, the process to enter Safe Mode differs for Apple Silicon (2020 and upwards) or Intel-based variants (before 2020).
Let’s start with the steps for an Apple Silicon PC:
- Shut down your Mac normally.
- Press and hold the power button until the Loading Startup Options appear.
- Select the startup disk.
- Press and hold your Shift key, then click Continue in Safe Mode.
- Wait for your Mac to restart automatically. In the login window, you should see Safe Boot in the menu bar, confirming that you’re in Safe Mode.
For an Intel-based Mac PC, follow these steps:
- Shut down your Mac.
- Press the power button to turn on your Mac, then immediately press and hold the Shift key until you see the login window.
- Log in to your Mac (you might be asked to log in twice). You should see Safe Boot in the login window, confirming that you’re in Safe Mode.
The point of Safe Mode is to review your PC for the presence of malware. You may know that malware is in your PC without being exactly sure which apps it has affected.
In Safe Mode on Windows, you can open Task Manager to see the CPU consumption of the apps that recently ran on your PC. If you observe apps consuming higher-than-usual resources, or system processes with unusual names, then these are common indicators of malicious activity.
Activity Monitor is the equivalent app on macOS. It displays the resource consumption of each app (and its internal processes) that recently ran on your Mac. You can scan for unusual patterns to detect malware behavior.
Whether or not you've been able to uncover the source of the problem, don’t fret. The next step is to fight the malware, where you’ve discovered it or if it is hiding in plain sight.
Install an antivirus tool
At this point, you can exit Safe Mode, and your next step is running an antivirus tool to fight the malware on your PC. An antivirus tool is the ultimate defender against malware, deploying sophisticated techniques to detect and flush it out from your PC.
Windows has a built-in antivirus tool called Microsoft Defender, and it excels at detecting and removing common malware threats. You can also download a third-party antivirus app to get complementary features like a virtual private network (VPN) and identity theft protection. Third-party tools are also often better at detecting the most sophisticated malware threats.
macOS has a built-in antivirus feature called XProtect. It’s not a separate antivirus app but instead runs in the background to detect and eliminate malware.
However, XProtect doesn’t always detect the most sophisticated forms of malware. macOS is already renowned for its security, so if you observe malware-like behavior on your Mac, it means the threat is serious and needs to be eliminated by an advanced third-party antivirus app.
Third-party antivirus apps are often freemium, with the free version unlocking access to core features, including malware scanning and removal, and the paid version unlocking complementary features. Selecting a suitable antivirus app may seem daunting, but don’t fret.
Run a deep malware scan
With your antivirus software up and running, you should run a deep scan of your PC to sniff out and remove malware wherever it may be hiding. Antivirus tools use various advanced techniques to identify malware, including:
Behavioral monitoring. This method involves monitoring your apps' real-time behavior for suspicious patterns, which are then flagged as malware.
Signature-based detection. This technique is the most common. It involves scanning your PC’s content against a known database of malware fingerprints, or “signatures.” If any fingerprint is detected, it’ll be flagged as malware.
Artificial intelligence (AI) analysis. Antivirus tools use AI algorithms to analyze your PC’s content for unusual patterns. This technique is effective at identifying the most complex malware threats that aren’t commonly known.
Sandboxing. When some antivirus tools detect a suspicious file, they’ll execute it in a virtual, isolated environment and observe the behavior to confirm whether it’s malware. Anything that happens in this virtual environment won’t affect your PC.
A deep scan can take anywhere from 30 minutes to several hours. The time it takes depends on the volume of files stored in your PC’s drive, which your PC has to scan.
After performing a deep scan, every malicious file will be quarantined to prevent damage. Then, you’ll be prompted to delete these files permanently from your PC.
After deletion, you should run a second deep scan to confirm that the remnants of each infected file have been permanently deleted. This way, any remnant you may have missed in the first step will be eliminated in the second, freeing your PC from the plague of malware.
Reset your web browsers
Malware can be self-replicating in a sneaky way. After infecting a PC, it often modifies the PC’s settings to redirect browser requests to malicious sites, where the PC can get re-infected again.
To be on the safe side, you should reset all your web browsers after deleting malware files.
On Google Chrome, you can do this by clicking the three vertical dots in the upper-right corner, then Settings > Reset settings. Finally, click Restore settings to their default values > Reset settings.
Microsoft Edge follows the same exact process, unsurprisingly, because both browsers are based on the open-source Chromium software.
To reset Apple’s Safari browser, click on the Safari menu in the top-left corner, then select Settings > Privacy > Manage Website Data. Finally, click Remove All and confirm the deletion so that you can start browsing afresh.
Preventing future malware infections
Having fixed a malware infection, the last thing you want is another re-infection that can have even worse consequences. You’ll need to take delicate steps to prevent malware from infecting your PC again. These steps include:
Exercise caution online
Most malware is spread online via unsuspecting downloads. To avoid facing another malware attack, caution is warranted when surfing the web.
You shouldn’t click on links or download attachments from unknown emails, as these are common malware vectors. Any link or email attachment you interact with should be from a trusted source.
Be wary of ads offering free software downloads, particularly those claiming to have found errors on your PC that need fixing. If you need to download a file, ensure it’s from a trusted website. For instance, if it’s an app, the best place to download it is from your operating system’s official app store or the app developer’s official website.
Run antivirus software
The antivirus software you downloaded to fix the malware isn’t a one-off tool. Consider it an inseparable part of your PC from now on.
It should always be turned on and allowed to run in the background. This way, the antivirus will readily scan any incoming file for malware and alert you to swiftly delete any infected file.
Antivirus tools can also scan your web browser requests for malicious links, if you provide the necessary permission.
Understandably, some users aren’t comfortable with all their browsing requests being processed by a third-party app. However, at a minimum, the antivirus tool should be allowed to scan your downloads for malware.
Avoid unknown USB drives
Most malware spreads online, but external USB drives remain another widely used vector. You shouldn’t insert any USB or hard disk drive into your PC, except your own or that of a trusted person.
Even after inserting a trusted drive, it should be scanned by your antivirus software before you transfer any files from it. Just as antivirus tools can sniff out malware from downloaded files, they can do the same on USB drives and protect you from further issues.
Regular app updates
Ensure all apps on your PC are updated regularly. App developers occasionally discover major security bugs and issue quick updates to patch them.
Downloading these updates keeps you safe when using various apps on your PC. You can turn on auto-updates for added convenience.
The same advice also applies to your operating system (OS). Always update your OS to the latest version available, as Microsoft and Apple usually end security support for old versions.
For instance, Microsoft has announced that it’ll end Windows 10 support in October 2025. If you still run Windows 10, you should explore updating to Windows 11 as soon as possible.
Be cautious with public WiFi
Public WiFi networks often lack robust encryption, leaving connected devices vulnerable to malware. With such malware, attackers can intercept sensitive data that passes through the WiFi network, such as login credentials.
You should avoid public WiFi networks except necessary. Then, always turn on a virtual private network (VPN) app before connecting to a public WiFi network. VPN apps encrypt your traffic through remote servers, preventing malicious actors from snooping on it.
They mask your IP address so that third parties can’t easily find the true source. Along with the security features, VPN apps also enable you to bypass content georestrictions when surfing the web.
Back up your data
You may have lost data when the malware infected your PC, and you definitely don’t want that to happen again.
While no one hopes for malware to re-infect their PC, you have to plan for the worst-case scenarios. Therefore, you need regular data backups so that you’ll retain access to your sensitive files even if a malware attack strikes again.
You can back up your whole PC or only the most important files. Windows and macOS have built-in cloud storage services – OneDrive and iCloud Drive, respectively – which you can use as a backup solution. These platforms let you choose specific files on your PC that will be backed up regularly.
You can also use external cloud storage and data backup services to achieve the same objective.
What’s important is that you choose a capable backup tool and obtain sufficient space to store your most important files.
