What is a Rootkit? Everything You Need to Know (2023)

By Tibor Moes / Updated: June 2023

What is a Rootkit? Everything You Need to Know (2023)

What is a Rootkit?

Imagine malicious software infiltrating your computer, stealing sensitive data, and hiding in plain sight, all without your knowledge. Sounds like a nightmare, doesn’t it? This is the reality of rootkit attacks, which have caused significant damage to individuals and organizations globally.

In this post, we dive deep into the world of rootkits and their detection, prevention, and removal. Arming you with the knowledge to protect your digital world.


  • A rootkit is a form of malware. It gives a hacker unauthorized remote control over your computer. All without your knowledge.

  • Rootkits hide their presence, manipulating systems to stay invisible, often used for malicious activities like stealing data.

  • Preventing rootkits involves regular antivirus system scans, frequent updates, and careful download practices from trusted sources only.

Don’t become a victim of cybercrime. Protect your devices with the best antivirus software and your privacy with the best VPN service.

Understanding Rootkits

A rootkit is a type of malware that hides within a device, granting its creator remote admin access to the operating system without detection. There are several types of rootkits, including firmware rootkits, kernel-mode rootkits, user-mode rootkits, virtualized rootkits, and bootloader rootkits. Recognizing a rootkit infection can be tricky, as they often disguise themselves and cause subtle changes in your system’s performance or security software. To combat these stealthy attackers, specialized removal tools and strategies are necessary.

Rootkits operate by targeting specific layers of your computer’s operating system or hardware components, with the ultimate goal of gaining unauthorized access and evading detection. Let’s now explore the objectives behind rootkit attacks and the common methods they use to infiltrate your system.

Rootkit Objectives

The main objectives of rootkits are to gain remote access, steal data, and hide malicious activities. Remote access allows hackers to control a computer system without permission, giving them the power to execute commands, install additional malware, and spy on user activities. Data theft involves extracting sensitive information, such as financial credentials, personal data, and intellectual property, which can be used for fraudulent activities or sold on the dark web.

Hiding malicious activities is crucial for rootkits to maintain their presence on the infected system. By concealing themselves and any associated malware, they can avoid detection by security software and continue to carry out their nefarious objectives without raising suspicion. To achieve this, rootkits employ various infection methods, as we will discuss in the next section.

Infection Methods

Rootkits commonly use a combination of a dropper and a loader to infiltrate a target system. The dropper imports the rootkit onto the victim’s computer, while the loader plants the malicious software onto the target system. Rootkits can be installed through email phishing campaigns, malicious files, PDFs or Word documents, shared drives that have been compromised, or downloading software from risky websites.

Social engineering, another common infection method, uses psychological manipulation to deceive people into divulging confidential information or performing actions that compromise their security. By exploiting human psychology and trust, attackers can trick users into installing rootkits, granting them access to the target system and its valuable data.

Software vulnerabilities can also be exploited by rootkits, as they can use unpatched security flaws to gain unauthorized access and perform malicious activities.

Types of Rootkits

Rootkits are classified into six categories based on their location and method of operation: firmware rootkits, user-mode rootkits, kernel-mode rootkits, virtual rootkits, memory rootkits, and bootloader rootkits. Firmware rootkits are malicious code that infects the software responsible for specific hardware components. It is stored in firmware, which can execute before the operating system loads.

User-mode rootkits can modify the behavior of application programming interfaces, intercepting system calls or filtering process output to conceal their presence. Kernel-mode rootkits target the kernel level of the operating system, making them particularly difficult to detect and remove.

Virtual rootkits run separately from the computer’s operating system, loading themselves underneath the original OS and putting it on a virtual machine, which further complicates their detection. Memory rootkits load into RAM and remain there until the system is restarted, at which point the RAM is cleared and the rootkit is removed.

Bootloader rootkits replace a computer’s original bootloader with a malicious one, altering the boot process and gaining control over the system.

Persistent Rootkits

Persistent rootkits are particularly troublesome, as they remain active even after a system reboot, making them harder to detect and remove. Rootkits often consist of malicious tools which can be used to steal banking credentials, passwords and even keystrokes. They can even disable antivirus software and launch distributed denial-of-service attacks. To stay hidden, persistent rootkits can gain boot persistence, allowing them to remain undetected unless specific tools are used to detect them.

Detecting and removing persistent rootkits can be challenging, requiring specialized removal tools or even reinstalling the operating system to ensure complete eradication. In contrast, non-persistent rootkits are easier to remove, but can still cause significant damage during their active period.

Non-Persistent Rootkits

Non-persistent rootkits only operate in memory and are removed upon reboot. However, they can still wreak havoc while active, stealing data, altering system files, and installing malicious software. Despite their temporary nature, the damage caused by non-persistent rootkits should not be underestimated.

Preventing non-persistent rootkits from infiltrating your system requires comprehensive cybersecurity solutions, regularly updating software, and practicing safe browsing habits. By staying vigilant and proactive, you can minimize the risk of falling victim to these insidious threats.

Identifying Rootkit Infections

Recognizing a rootkit infection can be a challenging task, as they often disguise themselves and cause subtle changes in your system’s performance or security software. However, there are some telltale signs that may indicate a rootkit infection on your computer or network.

In the following sections, we will discuss performance issues and security software disruption as potential indicators of a rootkit infection.

Performance Issues

Rootkits can cause a range of performance issues, from slow device performance and high CPU usage to crashes and other odd behaviors, such as changes in settings and poor performance of web browsers. Monitoring your system’s behavior and performance can help you identify potential rootkit infections and take appropriate action to remove them.

By analyzing data structures and system behavior, you can detect anomalies that may be indicative of a rootkit infection. While these performance issues may not always be a direct result of a rootkit infection, they can serve as an early warning sign that something is amiss in your system.

Security Software Disruption

Rootkits can also disable or interfere with antivirus programs and other security measures, making it difficult to detect and remove them. This disruption of security software can be a clear indication that a rootkit is present on your system. In such cases, specialized rootkit detection and removal tools may be required to effectively combat these elusive threats.

Awareness of the potential signs and symptoms of a rootkit infection is crucial for maintaining your computer’s security. By staying vigilant and proactive, you can minimize the risk of falling victim to these insidious threats.

Rootkit Detection Techniques

Detecting rootkits requires a combination of techniques, as no single method is foolproof. Signature scanning involves identifying rootkits by looking for specific malicious code signatures. Behavioral analysis detects rootkits by monitoring suspicious activities in the system. Memory dump analysis examines the memory dump of the system for any malicious code.

It’s essential to use multiple detection methods to increase the likelihood of identifying and removing rootkits from your system. By employing a comprehensive approach, you can enhance your system’s defenses against these elusive threats.

Rootkit Removal Strategies

Once a rootkit has been detected, it’s crucial to remove it from the infected system to prevent further damage and protect your sensitive data. Specialized removal tools and strategies are necessary for tackling these stealthy attackers.

In some cases, erasing and rebuilding your computer’s operating system may be the only way to completely get rid of a well-hidden rootkit. In the following sections, we will discuss specialized removal tools and the process of reinstalling the operating system as effective rootkit removal strategies.

Specialized Removal Tools

Several tools have been specifically designed for detecting and removing rootkits, such as McAfee Rootkit Remover, Bitdefender Rootkit Remover, Kaspersky TDSSKiller, and Norton. These specialized tools can help you combat rootkits by targeting their unique characteristics and behaviors. For example, TDSSKiller is a tool specifically created to detect and remove the TDSS rootkit.

Utilizing specialized removal tools can increase your chances of successfully detecting and removing rootkits from your system. However, in some instances, a more drastic approach may be necessary.

Reinstalling the Operating System

In extreme cases, erasing and rebuilding your computer’s operating system may be the only way to ensure complete eradication of a rootkit. This process involves backing up all important data, formatting the hard drive, and reinstalling the operating system. While this method can be effective in removing rootkits, it also carries risks, such as data loss, hardware incompatibility, and the chance of reinfection.

To avoid the need for such drastic measures, it’s essential to take preventive steps, such as using comprehensive cybersecurity solutions, keeping software up-to-date, and practicing safe browsing habits.

Preventing Rootkit Attacks

In the battle against rootkit attacks, prevention is the best defense. By employing comprehensive cybersecurity solutions, regularly updating software, and practicing safe browsing habits, you can minimize the likelihood of rootkit infections.

In the following sections, we will discuss these preventive measures in more detail.

Comprehensive Cybersecurity Solutions

Using a robust cybersecurity suite is the first line of defense against rootkits and other malware threats. Reputable anti-malware solutions provide real-time protection, scanning for and removing malicious software before it can infiltrate your system. In addition, keeping your security software up-to-date ensures that you have access to the latest security features and fixes for any existing vulnerabilities.

By employing comprehensive cybersecurity solutions, you can protect your system from rootkits, safeguarding your sensitive data and maintaining your computer’s security.

Regular Software Updates

Keeping your software and operating system up-to-date is essential for preventing rootkit infections. Updates can patch vulnerabilities that rootkits often exploit, making it harder for them to infiltrate your system. By regularly updating your software, you can ensure that any security flaws are fixed, and the latest security features are accessible.

Remember, software updates are not limited to your operating system. It’s also crucial to update your applications, plugins, and drivers to minimize potential security risks.

Safe Browsing Habits

Practicing safe browsing habits plays a significant role in protecting your system from rootkit infections. This includes avoiding suspicious websites, downloading files from trusted sources, and being cautious with email attachments.

Being aware of phishing scams and exercising caution when clicking on links or opening attachments can help prevent rootkits from infiltrating your computer. By adopting these preventive measures, you can minimize the risk of falling victim to rootkit attacks and maintain your system’s security.

Notable Rootkit Examples

Understanding the impact of rootkit attacks can be best illustrated through real-world examples. Notorious rootkits such as Necurs, Stuxnet, and ZeroAccess have caused significant damage to individuals and organizations worldwide. Necurs is known for its stealth and persistence, while Stuxnet, developed by the US and Israel, notoriously damaged Iran’s nuclear program. ZeroAccess is a kernel-mode rootkit that has infected over two million computers worldwide, turning them into part of a global botnet used by hackers for various cyberattacks.

These examples demonstrate the potential damage and far-reaching consequences of rootkit attacks, underscoring the importance of understanding, detecting, and preventing these elusive threats.


In conclusion, rootkits are a formidable threat in the world of cybersecurity. Understanding their objectives, infection methods, types, and detection and removal strategies is crucial for protecting your digital assets. By employing comprehensive cybersecurity solutions, keeping your software up-to-date, and practicing safe browsing habits, you can minimize the risk of rootkit infections and maintain a secure digital environment. Remember, the best defense against rootkits is a proactive approach, staying vigilant, and always being one step ahead of these stealthy attackers.

How to stay safe online:

  • Practice Strong Password Hygiene: Use a unique and complex password for each account. A password manager can help generate and store them. In addition, enable two-factor authentication (2FA) whenever available.
  • Invest in Your Safety: Buying the best antivirus for Windows 11 is key for your online security. A high-quality antivirus like Norton, McAfee, or Bitdefender will safeguard your PC from various online threats, including malware, ransomware, and spyware.
  • Be Wary of Phishing Attempts: Be cautious when receiving suspicious communications that ask for personal information. Legitimate businesses will never ask for sensitive details via email or text. Before clicking on any links, ensure the sender's authenticity.
  • Stay Informed. We cover a wide range of cybersecurity topics on our blog. And there are several credible sources offering threat reports and recommendations, such as NIST, CISA, FBI, ENISA, Symantec, Verizon, Cisco, Crowdstrike, and many more.

Happy surfing!

Frequently Asked Questions

Below are the most frequently asked questions.

What is a rootkit in simple terms?

Rootkits are malicious pieces of software created to hide and gain persistent access to a computer system, while at the same time trying to conceal itself from detection.

What are rootkit examples?

Rootkit is a malicious piece of software that gives access to an attacker over a computer system or network. Examples of rootkits include Vanquish, Aphex, and Hacker Defender.

Author: Tibor Moes

Author: Tibor Moes

Founder & Chief Editor at SoftwareLab

Tibor is a Dutch engineer and entrepreneur. He has tested security software since 2014.

Over the years, he has tested most of the best antivirus software for Windows, Mac, Android, and iOS, as well as many VPN providers.

He uses Norton to protect his devices, CyberGhost for his privacy, and Dashlane for his passwords.

This website is hosted on a Digital Ocean server via Cloudways and is built with DIVI on WordPress.

You can find him on LinkedIn or contact him here.

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