How to avoid computer viruses
Computer viruses are no laughing matter. Here’s some actionable tips for avoiding them and protecting your IT fleet.
Computer viruses can wreak havoc on your day, leading to lost data, compromised security, and significant downtime. If you've ever faced a virus-infected PC, you’ll know the frustration of dealing with that dreaded grey screen. You'll often need hours, if not days, to become operational again.
Added to this, the recent large-scale adoption of AI has created lots of new opportunities for hackers. Among other things, AI offers the possibility of self-learning viruses, which can adapt and spread with unprecedented success.
Thankfully, there are some tried-and-tested ways of avoiding most viruses. Here are some practical tips for detecting and preventing computer viruses and dealing with them once they're there.
In this article:
Tips for preventing computer viruses
Typically, computer viruses work because individuals or companies are not following best practices. Here are some tips to avoid them:
1. Always, always, have a backup
Why it’s important: Think of a backup as your safety net. If a virus corrupts your files, having one means you can restore your system quickly without losing critical data.
How to do it: Back up your files regularly with external hard drives, cloud storage, or network-attached storage (NAS). Make sure your backup solution runs automatically to minimize the risk of losing recent data.
2. Only download software from trusted sources
Why it’s important: So many viruses spread through infected software downloads. Downloading programs from untrusted sites can expose your system to malware.
How to do it: Always download software directly from the official website or a reputable third-party platform, such as the App Store or Google Play. Avoid freeware sites that bundle additional software, which are often malicious.
3. Be cautious of email attachments
Why it’s important: Email is a common vector for malware or phishing attacks. Opening an infected attachment can unleash a virus (and havoc) on your computer system.
How to do it: Make sure to verify the sender before opening any email attachments. Be wary of unexpected emails, even from known contacts.
Related reading: How to protect yourself from phishing and social engineering
4. Disable image previews in your email client
Why it’s important: Some computer viruses spread through image previews. Turning this feature off adds an extra layer of security.
How to do it: Change your email client's settings to turn off automatic image loading. Only manually approve images from trusted senders.
5. Use an anti-malware solution
Why it’s important: Anti-malware software can detect, quarantine, and remove viruses before they cause significant damage.
How to do it: Choose a reputable anti-malware solution and make sure that it's always running. Schedule regular full-system scans and always update the software with the latest virus definitions.
6. Use a firewall
Why it’s important: A firewall acts as a barrier between your computer and potential threats from the internet.
How to do it: Enable the built-in firewall on your operating system or use a third-party firewall. Configure it to block unauthorized access and monitor for suspicious activity.
7. Regularly update your OS and software
Why it’s important: Updates often include security patches that protect against newly discovered threats. This means skipping updates leaves you exposed to new threats.
How to do it: Enable automatic updates for your operating system and all installed software programs. If there aren't any automatic updates, check for and install software updates manually.
8. Monitor all devices proactively
Why it’s important: Viruses can spread quickly across devices. Keeping all devices secure ensures a safer overall environment.
How to do it: Use device monitoring tools to check for disabled firewalls, outdated software, and inactive antivirus solutions. Regularly review security settings on all connected devices.
Related reading: Endpoint management: a definitive guide
9. Use administrator rights
Why it’s important: Administrator rights can prevent unauthorized changes to your system, including those attempted by malware.
How to do it: Restrict administrative privileges to trusted users. You should need an admin password for all significant system settings or software installation changes.
Related reading: Password safety is evolving; can your business keep up?
10. Pay attention to virus warnings and notifications
Why it’s important: Ignoring antivirus warnings can lead to severe infections and data loss.
How to do it: Act immediately on any alerts from your antivirus software. Run a full system scan and follow the recommended steps to neutralize any detected threats.
11. Contact your IT department
Why it’s important: Early intervention can prevent a virus from spreading across a network.
How to do it: Immediately report suspicious activity or potential virus infections to your IT department. They can take steps to isolate and remove the threat.
12. Remove the virus properly
Why it’s important: By making sure the virus is totally gone, you will keep your system clean and prevent re-infection.
How to do it: Disconnect from the internet, boot into safe mode, and run a full system scan with your antivirus software. Follow the software's instructions to remove any detected viruses. If necessary, restore your system from a clean backup.
By following these strategies, you’ll be well placed to stay safe from most computer viruses. Get more tips by reading our comprehensive IT security handbook.
Understanding computer viruses
What are computer viruses?
A computer virus is a type of malware designed to replicate and spread to other programs or files, causing all kinds of damage. Unlike other malware types, viruses, like running an infected file, require a host program and human intervention to spread.
Examples of computer viruses
Ransomware, macros viruses, spyware, Trojan horses, adware, rootkits, polymorphic viruses, and computer worms.
Unfortunately, just like human viruses, there are countless kinds of computer viruses. We're also experiencing more and more of them: According to one report, 450,000 new kinds are detected every day.
The most common virus is the Trojan Horse, or Trojan. This usually gets hidden as an email attachment or a free-to-download file. Once downloaded, the malicious code can access your systems, spy on your online activity, or steal sensitive data.
Types of files viruses can infect
Computer viruses infect by attaching themselves to various file types, including:
- exe (executable files)
- com (command files)
- bat (batch files)
- cmd (command files)
- doc, .xls, .ppt (Microsoft Office files with macros)
These files require user interaction to activate the virus, such as opening or running the file.
Common symptoms of a computer virus
Some tell-tale signs that a computer virus has compromised your device:
Performance issues
Description: Viruses can slow down your computer by consuming system resources.
Symptoms: Slow performance, frequent crashes, and unresponsive computer programs.
Disappearing files
Description: Some viruses delete or hide files to cause data loss.
Symptom: Your files or folders will be missing or moved to different locations.
Disabled security software
Description: Viruses can turn off antivirus programs and firewalls to avoid detection.
Symptom: Suddenly disabled antivirus software or firewall.
Unusual behavior
Description: Viruses can cause erratic system behavior.
Symptom: Changes in system settings, unexpected pop-ups, or programs behaving strangely.
How to remove a virus
What to do if you find yourself dealing with a virus attack.
1. Boot into safe mode
Why it’s important: Safe mode loads only essential system files, preventing the virus from running.
How to do it:
- For Windows: Restart your computer and press F8 before Windows loads, then select Safe Mode.
- For Mac: Restart your computer and hold the Shift key until the Apple logo appears.
2. Run a full system scan
Why it’s important: A comprehensive scan can identify and quarantine or remove the virus. It can also stop it before spreading to other computers.
How to do it: Use your anti-malware software to perform a full system scan. Follow the software's instructions for removing detected threats.
3. Restart and verify
Why it’s important: Restarting means that you'll apply any changes made during the scan.
How to do it: After the scan, restart your computer normally. Then, check your system settings and important files to make sure that your system is virus-free.
4. Restore from backup if necessary
Why it’s important: If the virus caused a lot of damage, restoring from a backup can return your system to a clean state.
How to do it: Reinstall your operating system if needed and restore files from your backup.
Summary
Computer viruses have the potential to ruin your day and can have serious consequences for businesses of all sizes.
But as we've shown here, there are steps to take to avoid becoming infected with a computer virus. Regular backups, cautious downloading practices, vigilant email handling, and up-to-date security software all play a part.
With AI, we're also starting to see a new wave of ever-more sophisticated virus attacks. We don't know exactly where this will end up, but what we do know is that it will demand an even-more solid security posture
Is your IT fleet as secure as it should be?
There’s no need to compromise: TeamViewer offers enterprise-grade security for businesses of all sizes.
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