A rootkit is a type of malware that is designed to give hackers unauthorized access and control over a target device. The term “rootkit” originated from Unix and Linux operating systems, where the most privileged account admin is called the “root”. The term “kit” refers to applications that provide unauthorized root or admin-level access to a device. Rootkits can infect software, operating systems, hardware, and firmware, allowing cybercriminals to carry out various malicious activities.

What Is Rootkit?

A rootkit is software used by cybercriminals to gain control over a target computer or network. It is often composed of a collection of tools that enable hackers to have administrator-level control over the target device. Rootkits can be installed through phishing attacks, social engineering tactics, exploiting vulnerabilities in software or operating systems, or by bundling with other files such as infected PDFs or pirated media. Once installed, rootkits operate near or within the kernel of the operating system, giving them the ability to initiate commands and manipulate the computer’s functions.

Types Of rootkits

1. Hardware or firmware rootkit:

This type of rootkit targets the firmware of a device, such as the hard drive, router, or system’s BIOS. By infecting the firmware, hackers can install malware that is difficult to detect. Hardware or firmware rootkits allow cybercriminals to log keystrokes and monitor online activity, posing a significant threat to online safety.

2. Bootloader rootkit:

Bootloader rootkits attack the system responsible for loading the operating system on a computer. They replace the legitimate bootloader with a hacked one, activating the rootkit even before the operating system is fully loaded.

3. Memory rootkit:

Memory rootkits hide in a computer’s random-access memory (RAM) and use the computer’s resources to carry out malicious activities. They affect the performance of the computer’s RAM and disappear when the system is rebooted. While they have a short lifespan, they can still be a threat and may require additional steps to remove completely.

4. Application rootkit:

Application rootkits replace standard files in a computer with rootkit files and may alter the functionality of standard applications. These rootkits infect programs like Microsoft Office, Notepad, or Paint, allowing attackers to gain access to the computer whenever these programs are run. Detection of application rootkits can be difficult for users, but antivirus programs can detect them since they operate on the application layer.

5. Kernel mode rootkit:

Kernel mode rootkits target the core of the operating system, known as the kernel level. They not only provide access to files on the computer but also modify the functionality of the operating system by adding their own code. Kernel mode rootkits are among the most severe types of rootkits.

6. Virtual rootkits:

Virtual rootkits load themselves underneath the computer’s operating system and host the target operating system as a virtual machine. This allows them to intercept hardware calls made by the original operating system. Virtual rootkits do not need to modify the kernel to subvert the operating system, making them difficult to detect.

Why Are Rootkits So Dangerous?

Rootkits are dangerous for several reasons:

1. Sneaky infection methods:

Rootkits can spread through deceptive threat vectors such as corrupt downloads, spam emails, and exploit kits. Some rootkits rely on Trojans to breach a system’s security, making their presence difficult to detect.

2. Stealthy operation:

Unlike other types of malware, rootkits are designed to remain hidden and display minimal symptoms. They can bypass security software, making it challenging to detect and remove them. Some rootkits may require formatting the storage drive and reinstalling the operating system to completely eliminate them.

3. Multiple capabilities:

Rootkits are often referred to as the Swiss Army Knives of malware due to their diverse capabilities. They can steal login credentials and financial data, disable security protocols, log keystrokes, and more. Some rootkits can even turn a system into a bot to form a botnet and launch DDoS attacks against websites.

Is Rootkit A Virus?

Contrary to popular perception, a rootkit is not a virus. While a virus is a specific type of malware that corrupts data, a rootkit is a more advanced form of malware. Rootkits can deliver various forms of malware and manipulate the computer’s operating system to provide remote users with admin access. However, modern antivirus software that utilizes advanced security techniques can detect and remediate different types of malware, including rootkits.

What Are Rootkit Attacks?

Rootkit attacks are malicious activities carried out by threat actors using rootkits to gain unauthorized access and control over a target system. A rootkit is a type of malware that is specifically designed to hide its presence and evade detection by security software. It operates at a deep level within the system, often at the kernel or firmware level, making it difficult to detect and remove.

Rootkit attacks can be initiated through various means, including:

1. Infected Downloads:

Rootkits can be spread through infected downloads, such as malicious software or mobile applications. Users unknowingly install the rootkit along with the desired software, allowing it to gain control over the system.

2. Phishing Emails:

Threat actors may use social engineering techniques, such as phishing emails, to trick users into downloading and installing a rootkit. These emails often appear legitimate and may contain malicious attachments or links that lead to the installation of the rootkit.

3. Exploiting Vulnerabilities:

Rootkit attacks can also take advantage of vulnerabilities in software, operating systems, or firmware. By exploiting these weaknesses, threat actors can gain access to the system and install the rootkit without the user’s knowledge.

Rootkit Examples

1. Stuxnet:

Stuxnet is one of the most well-known and sophisticated rootkits in history. It was discovered in 2010 and targeted industrial control systems, specifically those used in Iran’s nuclear program. Stuxnet caused significant damage by manipulating programmable logic controllers (PLCs) and disrupting the operation of centrifuges.

2. Flame:

Flame, also known as Flamer or sKyWIper, is a complex and highly advanced rootkit that was primarily used for cyber espionage. It targeted computers in the Middle East, particularly in Iran and other countries in the region. Flame had the ability to gather sensitive information, capture screenshots, record audio, and log keystrokes.

3. Necurs:

Necurs is a rootkit that emerged in 2012 and is associated with elite cybercriminals in Eastern Europe. It gained attention for its technical complexity and its ability to evolve and adapt to different security measures. Necurs has been involved in various cybercriminal activities, including distributing malware and carrying out large-scale spam campaigns.

4. Zero Access:

ZeroAccess is a kernel mode rootkit that infected millions of computers worldwide. It operated by creating a botnet, a network of compromised computers under the control of the threat actors. The botnet was used for various malicious activities, such as click fraud, bitcoin mining, and distributing additional malware.

5. TDSS:

TDSS, also known as TDL or Alureon, is a rootkit that was first detected in 2008. It operates at the early stages of the operating system, making it difficult to detect and remove. TDSS is known for its ability to modify the master boot record (MBR) and redirect network traffic, allowing the threat actors to control the infected system.

Rootkit Injection

Rootkit injection refers to the process by which a rootkit is stealthily installed on a system. Threat actors use various techniques to inject rootkits into target systems, including:

1. Piggybacking:

Rootkits can be bundled with seemingly legitimate software or downloads. When users install the desired software, the rootkit silently installs alongside it, taking advantage of the user’s trust in the legitimate software.

2. Blended Threats:

In a blended threat scenario, threat actors combine the rootkit with other components, such as droppers and loaders, to exploit vulnerabilities and infiltrate the system. The dropper is responsible for installing the rootkit, while the loader ensures that the rootkit is loaded and executed during system startup.

An example of rootkit injection is the Sony BMG copy protection rootkit incident in 2005. Sony secretly bundled a rootkit with its Extended Copy Protection software, which was included on millions of Sony music CDs. The rootkit modified the host operating system to prevent users from making copies of the CDs. However, the rootkit had vulnerabilities that were later exploited by hackers, leading to unauthorized access to the affected systems.

How To Detect Rootkits

Detecting rootkits can be challenging due to their ability to hide and evade detection. However, there are several methods and indicators that can help in detecting rootkits:

1. Unusual System Behavior:

Rootkits can cause abnormal system behavior, such as frequent crashes, slow performance, or unexpected changes in settings. If you notice these signs, it may indicate the presence of a rootkit.

2. Network Anomalies:

Monitor network traffic for unusual patterns, excessive data transfer, or unexpected network connections. Rootkits may communicate with command-and-control servers or engage in malicious activities that can be detected through network monitoring.

3. Antivirus Scans:

Regularly perform full system scans using reputable antivirus software that includes rootkit detection capabilities. Keep your antivirus software up to date to ensure it can detect the latest rootkit variants.

4. Behavioral Analysis:

Use behavioral analysis tools that can detect rootkit-like behaviors, even if the specific rootkit is not known. These tools monitor system activities and can identify suspicious behaviors that may indicate the presence of a rootkit.

5. Offline Scanning:

If you suspect a rootkit infection, power down the infected system and perform a scan from a known clean system. This minimizes the rootkit’s ability to hide or interfere with the scan.

How To Get Rid Of Rootkit

Removing a rootkit can be a challenging and complex process. Here are some steps you can take to get rid of a rootkit:

1. Identify the rootkit:

Before attempting to remove a rootkit, it is crucial to identify the specific rootkit infecting your system. This can be done by running a rootkit scanner or using specialized rootkit detection tools. These tools can help detect and identify the presence of a rootkit on your system.

2. Use specialized removal tools:

Once you have identified the rootkit, you can use specialized removal tools designed to target and remove specific rootkits. Popular tools like TDSSKiller, Malwarebytes Anti-Rootkit, and Norton Power Eraser are effective in detecting and removing various types of rootkits.

3. Reinstall the operating system:

In some cases, if the rootkit is deeply embedded within the system and cannot be completely removed, the best solution may be to reinstall the operating system. This involves formatting the hard drive and reinstalling the operating system from scratch. Remember to back up your important files and data before proceeding with the reinstallation.

4. Seek professional help:

If you are unsure about removing a rootkit or if your attempts to remove it have been unsuccessful, it is advisable to seek professional assistance. Contacting a reputable cybersecurity expert or a computer technician can provide you with the expertise needed to effectively remove the rootkit from your system.

How To Remove Rootkit From Windows

Removing a rootkit from a Windows system requires careful steps to ensure complete removal. Here is a step-by-step guide:

1. Disconnect from the internet:

Before attempting to remove the rootkit, disconnect your computer from the internet. This prevents the rootkit from communicating with its command-and-control server and reduces the risk of further infection or data compromise.

2. Enter Safe Mode:

Restart your computer and enter Safe Mode. Safe Mode allows you to run the system with minimal drivers and processes, making it easier to detect and remove the rootkit. To enter Safe Mode, press the F8 key repeatedly during the boot-up process until the Advanced Boot Options menu appears. Select Safe Mode and press Enter.

3. Scan with antivirus software:

Run a full system scan using reputable antivirus software that includes rootkit detection capabilities. Ensure that your antivirus software is up to date to detect the latest rootkit variants. Allow the antivirus software to quarantine or remove any detected rootkit files.

4. Use specialized rootkit removal tools

If the antivirus scan does not detect or remove the rootkit, consider using specialized rootkit removal tools. Tools like GMER, Sophos Rootkit Removal Tool, and Kaspersky TDSSKiller are specifically designed to detect and remove rootkits from Windows systems. Download and run these tools, following the instructions provided by the software.

5. Remove suspicious files and registry entries:

If the rootkit is still present after running the specialized removal tools, you can manually search for and remove suspicious files and registry entries associated with the rootkit. Be cautious when modifying the registry, as any incorrect changes can cause system instability. It is recommended to back up the registry before making any changes.

6. Update your operating system and software:

After removing the rootkit, ensure that your operating system and installed software are up to date with the latest security patches and updates. This helps to prevent future infections and vulnerabilities.

7. Monitor for any unusual activity:

After removing the rootkit, monitor your system for any unusual activity or signs of reinfection. Keep your antivirus software and other security tools updated and regularly scan your system for any potential threats.

How To Remove Rootkit From Mac

On a Mac, it is important to keep your operating system up to date with the latest releases. Apple regularly includes security updates in their releases, which help remove malware, including rootkits. Apple has built-in security features to protect against malware, but it is important to note that there are no known rootkit detectors specifically designed for macOS. Therefore, if you suspect a rootkit on your Mac, the recommended course of action is to reinstall macOS.

Reinstalling the operating system removes most apps and rootkits from your machine. However, if the rootkit has infected the BIOS (Basic Input/Output System), it will require a repair to fix. In some cases, if the rootkit persists even after reinstalling macOS, it may be necessary to buy a new device to ensure complete removal of the rootkit.

Rootkit Protection And Removal

Rootkits are known to be one of the most challenging types of malware to remove from infected machines. While there is no guaranteed method for recovering a machine infiltrated by a rootkit, there are steps that users and organizations can take to protect their computers and remove the malware.

1. Back up vital data:

Before attempting to remove a rootkit, it is important to back up any important data and files that need to be retained from the infected machine. The removal process can be unpredictable, and the rootkit may have defensive measures that could affect or damage the machine’s performance.

2. Boot up in safe mode:

Many rootkits attempt to prevent users from installing security solutions or removing the malware. To overcome this, restart the machine in safe mode with networking. This limits the rootkit’s access and allows for better removal.

3. Use multiple rootkit scan tools:

Due to the wide range of rootkit families, not all rootkit scans will be capable of detecting them. It is recommended to use a combination of different rootkit scanners that offer different capabilities to increase the chances of detection.

4. Freeze remaining malware:

Removing the rootkit alone may not guarantee that the machine is completely clean. There may be other malware present that remains active or designed to evade rootkit scans. Using additional security solutions can freeze any remaining malware, allowing malware removal programs to clean up any malicious software effectively.

5. Advanced rootkit removal:

Some rootkit types are particularly difficult to remove. For example, firmware or hardware rootkits are unlikely to be removed by standard rootkit scans. In such cases, the user may need to back up and wipe their data from the machine and reinstall the operating system. However, if the rootkit has targeted the BIOS, even a wipe and reinstall may not be enough to remove the malicious software. This may require wiping and replacing the BIOS drive, along with a hard reset of the machine.

How To Prevent Rootkits

Prevention is often the best defense against rootkits due to their challenging nature to detect and remove. Here are some preventive measures to minimize the risk of rootkit infections:

1. Use a comprehensive cybersecurity solution:

Install a robust antivirus solution, such as Kaspersky Total Security, which provides full-scale protection from cyber threats and allows for rootkit scans.

2. Keep up-to-date:

Regularly update your operating system and all installed software. Software updates often include security patches and fixes for vulnerabilities that can be exploited by rootkits.

3. Be alert to phishing scams:

Phishing is a common method used to distribute rootkits. Be cautious when opening emails from unknown senders and avoid clicking on suspicious links or providing personal information.

4. Download files from trusted sources only:

Stick to reputable websites and download software from trusted sources. Be cautious of downloading files from unfamiliar websites or ignoring warnings from your web browser about unsafe websites.

5 Be alert to your computer’s behavior or performance:

Monitor your computer for any unexpected changes or unusual behavior. If you notice anything suspicious, investigate further to determine the cause.

6. Enable automatic updates:

Ensure that automatic updates are enabled for your operating system and all installed software. This ensures you receive the latest security patches and fixes promptly.

7. Use a firewall:

Implement a firewall to act as a barrier between your computer and the internet. Firewalls help block unauthorized access and prevent malicious software, including rootkits, from communicating with external servers.

8. Practice safe browsing habits:

Avoid visiting suspicious websites and clicking on pop-up ads that may contain malicious code. Stick to reputable websites and exercise caution when downloading files or clicking on links, even if they come from seemingly trustworthy sources.

9. Use strong and unique passwords:

Create strong, complex passwords for all your accounts and avoid using the same password for multiple accounts. This helps prevent unauthorized access to your system and minimizes the risk of rootkit infections.

10. Regularly scan your system:

Perform regular scans using reputable antivirus and anti-malware software to detect and remove any potential rootkits. Schedule automated scans to ensure continuous protection.

11. Be cautious with removable media:

Exercise caution when using external devices such as USB drives or external hard drives. Scan them with antivirus software before accessing any files to prevent potential rootkit infections.

12. Educate yourself and your employees:

Stay informed about the latest cybersecurity threats and educate yourself and your employees about safe online practices. This includes recognizing phishing attempts, avoiding suspicious downloads, and being cautious when sharing sensitive information online.

By following these preventive measures and staying proactive with your cybersecurity practices, you can significantly reduce the risk of rootkit infections and keep your Mac and other devices secure.