Virus-infected computer: what to do?

If you suspect your computer is infected with a virus or other malware, acting quickly can limit the damage and protect your personal information. This guide outlines the steps to take, what to avoid, and how to prevent future infections.

What is happening?

Malware, including viruses, worms, trojans, and spyware, is malicious software that can disrupt your computer's operation, steal data, or give attackers remote access. Common signs include unexpected pop-ups, slow performance, unknown programs, or unusual network activity.

Emergency warning

If you believe your computer is infected and you have sensitive data at risk, or if the infection is part of a wider security breach, contact local emergency services or a cybersecurity professional immediately. In many cases, disconnecting from the internet is the first critical step.

What to do first

1. Disconnect from the internet and networks: Unplug the Ethernet cable and turn off Wi-Fi. This prevents the malware from spreading or communicating with attackers.
2. Do not use the infected computer for sensitive tasks: Avoid online banking, email, or entering passwords until the system is cleaned.
3. Run a full antivirus scan: Use reputable security software (e.g., Windows Defender, Malwarebytes) to scan the entire system. Follow the software's recommendations to quarantine or remove threats.
4. Change passwords from a clean device: Use another computer or smartphone to change passwords for important accounts (email, banking, social media). Enable two-factor authentication where possible.
5. Seek professional help if needed: If the infection persists or you are unsure, consult a trusted IT professional or a computer repair service.

What NOT to do

• Do not ignore the problem: Malware can spread or cause further damage if left unchecked.
• Do not download unknown "fix" tools: Scammers often pose as antivirus solutions. Only use well-known security software.
• Do not pay ransom: If infected with ransomware, do not pay. Contact authorities and seek professional advice.
• Do not connect external drives until the system is clean, to avoid spreading the infection.

When to seek professional care

If you cannot remove the malware with antivirus software, if your data is encrypted (ransomware), or if you suspect identity theft, seek help from a cybersecurity expert or your local consumer protection agency.

What to monitor

• Check for unusual account activity (e.g., unauthorized logins, sent emails).
• Monitor your computer's performance and network traffic for signs of reinfection.
• Review financial statements for unauthorized charges.

How to prevent it

• Keep your operating system and software updated.
• Use reputable antivirus software and keep it updated.
• Be cautious with email attachments and links from unknown senders.
• Back up important data regularly to an external drive or cloud service.

After cleaning your system, consider a full reset or reinstall of the operating system if the infection was severe. Stay vigilant and practice safe browsing habits to avoid future infections.

This information is for general guidance only. For serious security incidents, consult a professional.