Definition and Explanation of Rootkit Programs

Rootkit programs are a type of malicious software designed to give hackers the ability to access a target device and control its contents. While most rootkit programs affect software and the operating system, some can impact the device's hardware components and firmware as well. Rootkit programs are known for their high level of sophistication in concealing their presence, making them both active and hidden.

Rootkit programs gain unauthorized access and open the door for cybercriminals to steal personal data and financial information. They can also install malware or use compromised devices as part of a botnet to distribute malware and participate in Distributed Denial of Service (DDoS) attacks.

The term "rootkit" is derived from Unix and Linux operating systems, where the superuser account, which has the highest privileges, is named "root," and applications that allow unauthorized access at the root level are referred to as "kit."

What Are Rootkit Programs?

Rootkit programs are software tools used by cybercriminals to control a targeted computer or network. They may sometimes appear as a single piece of software but are often composed of various components that grant hackers privileged access to the target device.

Cybercriminals can install rootkit programs through various methods:

Social Engineering: The most common method is through phishing attacks or other social engineering tactics, where victims unknowingly download and install malicious software that operates stealthily alongside other processes on their devices, granting hackers control over the system.

Exploiting Security Vulnerabilities: Exploiting security vulnerabilities, such as unpatched software or operating systems, allows rootkits to be forcibly introduced into a computer.

Bundling with Malware: Malware can be bundled with other files, such as infected PDFs or pirated media, or obtained from dubious external sources.

Rootkit programs operate close to or within the operating system kernel, giving them the ability to issue commands to the computer. Anything that uses an operating system can potentially be a target for rootkit programs, including devices like refrigerators or IoT (Internet of Things) appliances.

Rootkit programs can hide keyloggers and record every keystroke without the user's consent, making it easy for cybercriminals to steal personal data, such as credit card information and banking details. They can also allow hackers to use your computer to launch DDoS attacks, send spam emails, and even disable or remove security software.

Some rootkit programs serve legitimate and lawful purposes, such as providing remote IT support or assisting law enforcement agencies in their tasks. However, most are used for malicious purposes. What makes rootkit programs extremely dangerous is the diversity of malicious software they can deploy, which can manipulate the computer's operating system and provide remote access to users.

Types of Rootkit Programs:

Hardware or Firmware Rootkits: 

These rootkits affect the hardware components or firmware of a device, such as the hard drive or router. They are less common but pose a significant security threat.

Bootkit Rootkits:

 Bootkit rootkits target the system's boot mechanism, replacing the official boot loader with a compromised version. This allows the rootkit to activate even before the operating system fully loads.

Memory Rootkits: 

Memory rootkits reside in a computer's RAM (Random Access Memory) and utilize the computer's resources to execute malicious activities in the background. They can be challenging to detect as they disappear upon system reboot.

Application Rootkits:

 Application rootkits replace legitimate application files with malicious versions, potentially altering the normal behavior of those applications. They often go unnoticed as they operate within the application layer.

Kernel or Kernel-Mode Rootkits:

Kernel-mode rootkits are among the most dangerous, as they manipulate the core of the operating system (the kernel). They can modify the operating system's behavior and are difficult to detect.

Virtual Rootkits:

 Virtual rootkits load themselves as virtual machine monitors, allowing them to control the host operating system from a virtual environment. These are particularly challenging to identify.

Examples of Rootkit Programs

Stuxnet

One of the most famous rootkit programs in history is Stuxnet, a malicious computer worm discovered in 2010, believed to have been developed in 2005. Stuxnet caused significant damage to the Iranian nuclear program, and although the United States or Israel did not officially acknowledge responsibility, there is strong belief that it was a cyber weapon created collaboratively between the two countries as part of a known cooperative effort referred to as the "Olympic Games."

Other notable examples of rootkit programs include:

Flame

Cybersecurity experts discovered Flame in 2012, a rootkit program primarily used for cyber espionage in the Middle East. Flame is also known by other names such as Flamer, sKyWIper, and Skywiper. It can affect the entire operating system of a computer, allowing it to monitor network traffic, capture screenshots, record audio, and capture keyboard strokes from the infected device. The perpetrators behind the malicious Flame program have not been identified, but research suggests they used 80 servers located on three different continents to access infected computers.

Necurs

Necurs emerged as a rootkit program in 2012, with reports indicating its discovery in 83,000 infections that year. Necurs has been linked to elite cybercriminals in Eastern Europe and is known for its technical complexity and adaptability.

ZeroAccess

Cybersecurity experts discovered ZeroAccess in 2011, a rootkit program designed to install a kernel mode rootkit on more than two million computers worldwide. Instead of directly impacting the functionality of infected computers, this rootkit program downloads and installs malicious software on the compromised device, making it part of a global botnet used by hackers to carry out cyberattacks. ZeroAccess remains active to this day.

TDSS

TDSS, a rootkit program, was first discovered in 2008. It is similar to bootkit rootkits because it loads and executes itself in the early stages of the operating system, making it difficult to detect and remove.

How to Detect Rootkit Programs

Detecting the presence of a rootkit program on a computer can be challenging, as this type of malicious software is designed to remain hidden. Rootkit programs can also disable security software, making the task even more difficult. As a result, malicious rootkit programs can persist on your computer for extended periods of time and cause significant harm.

Possible signs of rootkit programs may include:

Blue Screens

Many error messages in the Windows operating system, known as Blue Screens of Death (BSOD), may appear when the computer requires frequent restarts.

Unusual Browser Behavior

This can include unfamiliar bookmarks or link redirections.

Sluggish Performance

Your computer may take a long time to start up, operate slowly, or freeze frequently, and it may fail to respond to mouse or keyboard inputs.

Unauthorized System Setting Changes

Examples might include changes to the screensaver, hiding the taskbar, or displaying incorrect date and time, even if you haven't made any changes yourself.

Internet Pages Not Working Properly

Internet pages or network activities may intermittently fail or not function correctly due to excessive network traffic.

Searching for rootkit programs is the best way to detect rootkit infections, and antivirus applications can do this. If you suspect a rootkit virus infection, one method of detection is to shut down the computer and perform a scan using a reputable cleanup tool.

Behavioral analysis is another method to detect rootkit programs. Instead of searching for the rootkit program itself, you look for behaviors similar to rootkit programs. Targeted scanning works well if you already suspect that your system is behaving unusually, but behavioral analysis might alert you to a suite of rootkit tools before you even realize you're under attack.

How to Remove Rootkit Programs

Removing rootkit programs is a complex process and typically requires specialized tools, such as the TDSSKiller tool from Kaspersky, which can detect and remove TDSS-type rootkits. Sometimes, the only way to completely eliminate a well-hidden rootkit program is to wipe the computer's operating system and rebuild it from scratch.

How to Remove Rootkit Programs from Windows

On Windows, removal usually involves running a scan, and in cases of deep infection, the only way to get rid of a rootkit program is by reinstalling Windows. It's best to do this through an external media device rather than using the built-in Windows installer. However, some rootkit programs infect the BIOS, requiring you to address that as well. If the rootkit program persists after the fix, you may need to purchase a new computer.

How to Remove Rootkit Programs from Mac

Always keep your Mac's software up to date, as macOS updates not only add new features but also remove malicious software, including rootkit programs. Apple's devices come with built-in security features to protect against malware, but there are no rootkit detection tools on macOS, so if you suspect a rootkit program on your Mac, you should reinstall macOS, as this will remove most applications and rootkit programs from your device. As mentioned above, if your BIOS is infected with a rootkit program, it will require repairs. If the rootkit program persists after the repair, you may need to purchase a new computer.

How to Protect Against Rootkit Programs

Rootkit programs can be dangerous and hard to detect, so it's important to stay vigilant when browsing the internet or downloading software. Many preventive measures you take to avoid computer viruses also help reduce the risk of rootkit programs:

Use Comprehensive Security Software

Be proactive in securing your devices by installing comprehensive and advanced antivirus software. Kaspersky Total Security, for example, provides complete protection against cyber threats and allows you to perform scans for rootkit programs.

Keep Software Up to Date

Regular software updates are crucial to staying secure and preventing hackers from infecting you with malware, so keep all your software and operating systems up to date to avoid falling victim to rootkit attacks exploiting security vulnerabilities.

Be Alert to Deceptive Tactics

Deception and phishing attacks are forms of social engineering where hackers use email to deceive users into divulging financial information or downloading malicious software, such as rootkit programs. To prevent rootkit programs from infecting your device, avoid opening email messages from unknown sources, especially if you don't know the sender, and do not open any links unless you are sure they are safe.

Only Download Files from Trusted Sources

Be cautious when opening attachments and avoid opening attachments from people you don't know to prevent rootkit programs from installing on your device. Similarly, only download software from legitimate, well-known sources, and do not ignore your browser's warnings when it tells you a website you're trying to visit is not secure.

Pay Attention to Computer Behavior or Performance

Behavioral issues can indicate a rootkit infection, so be alert to unexpected changes and try to identify the cause.

Rootkit programs are among the most challenging types of malware to detect and remove. Because discovering them after infection is difficult, prevention is the best way to protect yourself from them. To ensure ongoing protection, never stop learning about cybersecurity threats.