Zombie Computers: What Are They And How Do They Work?

Mention the word ‘zombie’, and people’s minds will undoubtedly be filled with images straight out of a horror movie. However, in recent years, the term ‘zombie’ has been extended to the tech industry. But what is a zombie computer, and how does it work? Let us share more details about this term and how you can prevent your devices from being compromised.

What is a zombie computer?

A zombie computer refers to any device that has been compromised by a virus or hacker. For example, if a hacker were to breach your computer and install the malware in it, they have effectively ‘infected’ your device, turning it into a zombie computer they can remotely manipulate to spread the virus to further victims.
Most owners of zombie computers rarely ever realise that their systems have been compromised and are being used as a tool by malicious entities. Apart from spreading the malware and infecting other systems, zombie computers are also used in distributed denial-of-service (DDoS) attacks in conjunction with botnets – a network of zombified computers controlled by a single attacking party.

What happens when my computer becomes a zombie?

Unfortunately, it can be a challenge to detect whether your machine has become a zombie computer. Since these compromised systems are primarily used for infecting other computers, the hackers that propagate these attacks are generally adept at hiding their code to avoid detection. Thus, it is possible for you not to notice anything amiss when using your devices.
However, there exist subtle clues that will indicate any adverse change in your computing system. If your computer has been infected, you will notice the following issues:

  • Intermittent and random crashes
  • Overall slower speeds
  • Antivirus software warning you of potential security threats
  • High CPU or RAM usage
  • Missing files or folders
  • Unknown processes running in the background

How can I protect my computer from becoming a zombie?

Caution and common sense are two of the most effective lines of defence to safeguard your devices from being compromised. Let us share what you can do to protect your computer from being infected.

1. Avoid visiting suspicious websites

Suspicious websites are illegitimate pages that often take on the appearance of official ones, such as banking websites, to trick users into divulging their credentials and other sensitive information.
Let us share a few tips to help you better detect malicious websites:

  • Use common sense – If a website looks unsafe and does not inspire confidence at first glance or outright asks you for sensitive personal information, proceed no further and exit the site immediately.
  • Doublecheck the URL – Pay close attention to the websites you frequent and note down their URLs. Often, a suspicious website will have a near-identical URL to the one it is replicating, but with a few minor differences, like an additional character or two. An accidental typo may lead you to this fraudulent version instead of the official site you intended to visit.
  • Check the properties of hyperlinks – With a simple right-click of the mouse and choosing the ‘Properties’ option, you can easily see where a link intends to redirect you. If it is different from what the content claims to direct you to, avoid clicking on it.

2. Be mindful of what you download and install

Often, malware is able to infiltrate your system because you unwittingly granted it access to your devices by downloading and installing shady files. Although modern antivirus software is now more adept at spotting and removing malicious software before it can cause problems, it is best to avoid being reliant on them and always be vigilant when downloading anything from the internet.

3. Avoid clicking on suspicious links or email attachments

Phishing is a common cybersecurity attack that is typically carried out via email. The email may contain an enticing title to prompt users to open attachments containing the malware payload or click on a link redirecting the user to a website that hosts the virus.
As a rule of thumb, always check the details of the addressee to see if they are unfamiliar or suspicious before opening the email. If you do not recognise the sender’s address, refrain from clicking the email and proceed to delete it immediately.


Zombie computers are a cybersecurity risk that should not be taken lightly. By remaining vigilant when using your devices to access the internet, you can prevent such a scenario from occurring to you. Furthermore, it is advisable to read up on the best security practices to adopt, especially if you are working from home, to prevent your devices from being compromised.
At BridgingMinds, we provide a vast array of IT security courses to equip you with the relevant knowledge to safeguard your devices. Our instructors regularly keep up-to-date with the best cybersecurity practices, so you can rest easy knowing the knowledge you have gained from our classes will stand you in good stead when faced with the latest cybersecurity threats.