Update Date: 01.09.2023
A rootkit is a form of malware developed to provide hackers access to and control over a target device. Certain rootkits have the ability to infect your computer's hardware and firmware in addition to its software and operating system. Rootkits are skilled at hiding their existence, yet they are active while doing so.
Rootkits provide hackers unauthorized access to computers, allowing them to steal financial and personal data, install malware, or utilize computers as part of a botnet to send spam and take part in DDoS (distributed denial of service) assaults.
The term "rootkit" comes from the Unix and Linux operating systems, where the moniker "root" refers to the administrator with the greatest privileges. The "kit" refers to the software that permits illegal root or admin-level access to the device.
In this article, we will discuss the following topics over Rootkit:
What is a rootkit, and how does it differ from other types of malware?
What are the risks of having a rootkit on your system, and how can it be used by attackers?
What are some of the signs that a system may be infected with a rootkit?
How to detect and prevent rootkits (How to defend against rootkits)?
What are examples of rootkit attacks?
What are the types of rootkits?
What are the injection methods of rootkits?
How to remove rootkits?
Which tools can be used for rootkit removal?
What is a Rootkit?
A rootkit is a piece of software that hackers employ to take over a target computer or network. Although rootkits frequently consist of a group of programs that provide hackers administrator-level access to the target device, they occasionally emerge as a single piece of software. There are several techniques for hackers to install rootkits on target computers:
Phishing and other forms of social engineering attacks are the most frequent. Unknowingly, victims download and set up malware that gives hackers access to nearly every part of the operating system by hiding among other processes running on their computers.
Another method involves pushing the rootkit onto the machine by taking advantage of a vulnerability, which is a flaw in software or an out-of-date operating system.
Moreover, malware can be packaged with other items like corrupt documents, pirated movies, or programs downloaded from dubious third-party app stores.
Rootkits send orders to the computer because they operate close to or inside the operating system's kernel. As the Internet of Things develops, appliances like your fridge and thermostat may become possible targets for rootkits since they employ an operating system.
Keyloggers that secretly record your keystrokes are hidden by rootkits. Because of this, it is simple for cybercriminals to obtain your personal data, including credit card or online banking information. Rootkits provide hackers the ability to launch DDoS assaults or send spam emails from your machine. They even have the ability to disable or delete security software.
Certain rootkits are employed for legal reasons, such as supporting law enforcement or offering remote IT support. Nonetheless, they are typically employed for evil. The different types of malware rootkits spread, which affect an operating system and grant remote users admin access, are what make them so hazardous.
How does Rootkit Differ from Other Types of Malware?
The differences between a rootkit and other types of malicious software are explained in this section.
Is Keylogger a rootkit?
No. A rootkit is a piece of computer code that uses misdirection strategies with software already installed on your system to conceal objects, including itself. Although they are connected to them, backdoors, keyloggers, and vulnerabilities are not rootkits. In order to access your computer, a rootkit could employ an exploit (or, for that matter, social engineering or direct attacks). Once it's there, it may conceal a keylogger, a backdoor, or any number of other things.
Is rootkit malware or virus?
Contrary to common belief, malware is what a rootkit is instead of a virus. Indeed, that may sound perplexing. A rootkit is a far more sophisticated form of malware than a virus, which just corrupts data. Luckily, contemporary antivirus software can remove a variety of malware, from viruses and worms to ransomware, Trojans, and even certain rootkits, by utilizing cutting-edge protection approaches like behavioral heuristics.
Is Trojan a rootkit?
A rootkit is a group of malicious programs that provides access to network administrators. A Trojan Horse is a type of malware that collects crucial data from a computer network or system. The primary goal of a rootkit is to steal identifying information, frequently in order to take over a machine. Information theft is the Trojan horse's primary goal. A rootkit's detection and removal are difficult processes that frequently demand for the usage of specialist tools. The antivirus program finds Trojan horses.
Is rootkit a spyware?
Rootkit is a collection of malicious software that gives network administrators access. Spyware is a sort of program designed to collect your personal information. The primary goal of a rootkit is to steal identification information, frequently in order to take over a machine. The main goal of the spyware is to keep an eye on system activities. Finding and eliminating a rootkit is a difficult task that frequently calls for the use of specialist tools. The anti-spyware tool can find and get rid of spyware.
What are the Risks of having a rootkit on your system, and how can it be used by attackers?
Some possible outcomes of a rootkit assault include the ones listed below:
Causes a malware infection: A rootkit places harmful software, including viruses, Trojan horses, worms, ransomware, spyware, adware, and other destructive programs, on a computer, system, or network, jeopardizing the device's functionality or the privacy of its data.
Removes files: Rootkits insert themselves into a system, network, or device through a backdoor. This occurs during login or is the consequence of a security or OS software flaw. Once inside, the rootkit runs programs that steal or remove data automatically.
Intercepts personal information: Keyloggers, which record keystrokes without the user's agreement, are frequently used by rootkits referred to as payload rootkits. In other instances, these rootkits send spam emails that, when opened by recipients, install the rootkits. In both situations, the rootkit takes private data, including credit card numbers and information from online banking, which is then given to thieves.
Steals private information: Rootkits introduce malware into systems, networks, and computers that hunts for confidential and sensitive data, generally with the intention of selling the information or disclosing it to unauthorized parties. Rootkits collect confidential data via keyloggers, screen scrapers, spyware, adware, backdoors, and bots, among other techniques.
Changes the system's settings: After gaining access to a system, network, or computer, a rootkit can change the settings of the system. It has the ability to set up a stealth mode that makes it difficult for traditional security tools to find it. Moreover, rootkits have the ability to develop a permanent state of existence that makes it challenging or impossible to remove them, even after a system restart. A rootkit has the power to alter security authorisation rights to enable access or offer an attacker continued access.
What are the Signs that a system is infected with a rootkit?
Potential rootkit malware warning indicators are as follows:
Blue screen: The need to reboot your computer frequently while seeing a lot of Windows error messages or blue screens with white writing (sometimes known as "the blue screen of death").
Strange web browser actions: Unrecognized bookmarks or link redirection are examples of this.
Device performance issues: Your device can be slow to start, operate slowly, or frequently freeze. Moreover, it could not react to input from the keyboard or mouse.
Windows settings are modified without authorization: Examples include the taskbar concealing itself, your screensaver changing, or the wrong date and time appearing even if you haven't altered anything.
Web sites don't operate correctly: Due to high network traffic, web pages or network activities can look inconsistently or don't perform properly.
How to Detect & Prevent rootkits?
Finding the rootkit on a computer is challenging since that rootkit malware is made specifically to remain hidden. The process is made more difficult by the fact that rootkits disable security software. Because of this, rootkit malware may stay on your machine for a long time and cause serious harm.
The best approach to finding a rootkit infection is to run a rootkit scan, which your antivirus program can do. Shutting down the computer and running the scan from a known-clean system are two ways to find the infection if you think there may be a rootkit virus present.
A further technique for rootkit identification is behavioral analysis. This implies that you search for rootkit-like behavior rather than the actual rootkit. A behavioral analysis may spot a rootkit before you are aware that you are being attacked, in contrast to targeted scans, which are effective when you are aware that the system is acting strangely.
It's crucial to be cautious while using the internet or installing software because rootkits might be harmful and challenging to discover. Several of the same precautionary procedures you take to avoid computer viruses also assist to decrease the risk of rootkits:
Implement a thorough cyber security program: Install a complete and cutting-edge antivirus program on all of your devices to be proactive about protecting them.
Keep up-to-date: Regular software updates are crucial for maintaining your security and avoiding malware infection from hackers. Keep all of your software and operating system up to date to stave off rootkit assaults that exploit holes.
Recognize phishing frauds: Phishing is a sort of social engineering assault in which con artists use emails to deceive victims into divulging their financial information or downloading harmful software, including rootkits. Avoid clicking on links in strange emails, especially if the sender is unknown to you, to stop rootkits from gaining access to your computer. Never click on a link if you aren't convinced it's reliable.
Always get materials from reputable sources: To prevent a rootkit from being placed on your computer, use caution when opening attachments and stay away from opening attachments from individuals you don't know. Always get software from trustworthy websites. When your web browser alerts you that a website you are attempting to access is hazardous, don't disregard it.
Pay attention to how your computer behaves or functions: Problematic behavior is a sign that a rootkit is active. Keep an eye out for any sudden changes and attempt to determine their cause.
Figure 1. How to Detect & Prevent rootkits
What are Examples of Rootkit Attacks?
Here are some examples of rootkit attacks:
Sony BMG Rootkit: Sony BMG required a solution in 2005 following years of declining music revenues caused by the emergence of Napster and other music pirate platforms. They employed a number of applications to obstruct CD copying software in order to make it more difficult to transfer music from CDs to computers. Security experts categorized these applications as rootkits because they concealed themselves from users and the operating system.
Stuxnet: Stuxnet, a dangerous computer worm that was found in 2010 and is thought to have been in development since 2005, is one of the most famous rootkits in history. The Iranian nuclear program suffered severe harm as a result of Stuxnet. Although neither nation took ownership, it is commonly thought to have been a cyberweapon jointly developed by the US and Israel as part of the Olympic Games.
Duqu: A group of computer malware known as Duqu was found on September 1, 2011, and according to Kaspersky Laboratories, it is connected to the Stuxnet worm and was developed by Unit 8200. The zero-day flaw in Microsoft Windows has been used by Duqu. The danger was identified, the malware was examined, and a 60-page report was written by the Budapest University of Technology and Economics' Laboratory of Cryptography and System Security (CrySyS Lab) calling the threat Duqu. The prefix "DQ" that Duqu appends to the names of the files it generates is how it received its name.
Flame: Flame is a rootkit that was first deployed in the Middle East for cyber espionage in 2012, according to cybersecurity experts. Flame, also known as Flamer, sKyWIper, and Skywiper, alters the whole operating system of a computer, enabling it to record keystrokes, monitor traffic, and take screenshots and audio. Researchers believe the Flame hackers utilized 80 servers spread across three continents to access affected machines, although they have not yet been identified.
Necurs: Necurs first appeared as a rootkit in 2012, when it was purportedly found in 83,000 infections. Necurs is regarded as a standout owing to its technical difficulty and capacity for evolution, and it is often associated with the most skilled cybercriminals in Eastern Europe.
ZeroAccess: ZeroAccess, a kernel mode rootkit that affected more than 2 million machines worldwide, was found by cybersecurity professionals in 2011. Instead of altering the infected computer's operation directly, this rootkit downloads and installs malware on it, adding it to a global botnet that hackers use to launch cyberattacks. Today, ZeroAccess is being used.
TDSS: The TDSS rootkit was initially discovered in 2008. This is similar to bootloader rootkits in that it loads and operates in the early phases of the operating system, making detection and removal difficult.
TDL-4: Alureon, also known as TDL-4, is a trojan and rootkit designed to steal data by monitoring a system's network traffic and looking for sensitive user data such as social security numbers, credit card numbers, PayPal information, and banking usernames and passwords. Alureon was found to be the source of a wave of BSoDs on some 32-bit Microsoft Windows PCs after a number of customer complaints. Because the update, MS10-015, violated the malware author's presumptions, it caused these crashes.
The Greek Wiretapping Scandal: The so-called Greek Watergate was a massive phone-tapping scandal that started to emerge in 2005. High-ranking Greek government employees' and civil servants' phones on the Vodafone network were found to be being watched and recorded. Unknown attackers installed a rootkit that listened in on conversations and put backdoors on the network so they could secretly carry out more eavesdropping operations.
Zacinlo: In 2012, the nasty adware rootkit known as Zacinlo initially surfaced. It started displaying a new rootkit component in 2017 that gave it the ability to go through Windows 10 security measures. Most of Zacinlo's victims are in the United States. It appears that the rootkit feature was implemented to enable the virus to remain undiscovered on computers for as long as feasible. It stops several security programs from running, such as Malwarebytes, Panda, and Symantec.
What are the Types of Rootkits?
Different types of rootkits are listed below:
Kernel mode rootkits: Because they attack the fundamental foundation of your operating system, kernel-mode rootkits (i.e., the kernel level) are one of the most dangerous varieties of this threat. By inserting their own code, hackers can modify the operation of your operating system in addition to gaining access to the information on your computer.
Bootloader rootkit: The operating system on a computer is loaded through the bootloader process. Attacks on this system by bootloader rootkits cause your computer's authentic bootloader to be replaced with a compromised one. Even before your computer's operating system is fully loaded, this launches the rootkit.
Memory rootkit: Memory rootkits conceal themselves in the random-access memory (RAM) of your computer and utilize its resources to run harmful processes in the background. Memory rootkits impede the RAM performance of your machine. Memory rootkits vanish as soon as you reboot the system because they only exist in RAM and don't insert permanent code, however, occasionally more effort is required to remove them. Due to their brief existence, they are frequently not seen as a serious danger.
Hardware or firmware rootkit: Hard drives, routers, and your system's BIOS, which is the software loaded on a little memory chip in your computer's motherboard, can all be impacted by hardware or firmware rootkits. In order to install malware that is difficult to detect, they target the firmware of your device rather than your operating system. They allow hackers to collect your keystrokes and watch your internet behavior since they have an impact on hardware. However less frequent than other varieties, hardware or firmware rootkits pose a serious risk to internet security.
Application rootkit: Application rootkits even alter how regular apps function by replacing standard files on your computer with rootkit files. Programs like Microsoft Word, Notepad, or Paint become infected by these rootkits. Every time you use those apps, an attacker has access to your computer. While rootkit identification is challenging for users since infected programs continue to function properly, antivirus software can find them because they both operate on the application layer.
Virtual rootkits: Under the operating system of the machine, a virtual rootkit loads. After that, it runs the target operating systems as virtual machines, enabling it to eavesdrop on hardware calls the original operating system was making. This kind of rootkit is exceedingly challenging to find. And it does not require changing the kernel to compromise the operating system.
What are the Injection Methods of Rootkits?
A rootkit is covertly installed on your machine via a variety of techniques. Rootkit injection methods are explained below:
Piggybacking: Using seemingly reliable software, rootkits can be installed unintentionally by users. The rootkit discreetly installs on the machine when the administrator approves the software's installation.
Combined Threat: A rootkit cannot independently infect target machines. Attackers create a hybrid threat to exploit many vulnerabilities and enter a system in order to distribute a rootkit. The rootkit is combined with a loader and a dropper, two additional components, to do this. A rootkit installation application or file known as a "dropper" is used to set up a target machine with a rootkit. Droppers can be spread in a variety of methods, such as by social engineering or a brute-force assault in which the culprit uses software to continuously try to guess the root username and password of a system. Malicious code known as a loader is launched once a user starts the dropper software by opening or running a file. To guarantee that the rootkit loads alongside the target system, the loader takes use of security flaws. For instance, a kernel-level rootkit may employ a loader that takes advantage of a flaw in Linux to swap out operating system code for a modified Loadable Kernel Module.
How to Remove Rootkits?
Rootkit removal is a difficult operation that often calls for specialist tools, such as the Kaspersky TDSSKiller application, which can identify and eliminate the TDSS rootkit. Sometimes wiping your computer's operating system clean and starting over is the only method to completely remove a well-hidden rootkit.
Running a scan is often required to get rid of the Windows rootkit. Reinstalling Windows is the only way to get rid of a rootkit if it has been deeply infected. Using an external media device is preferable to using Windows' default installer for this. Certain rootkits infect the BIOS, which has to be repaired. After a repair, if you still have a rootkit, you might need to buy a new computer.
Keep abreast of new releases to get rid of a rootkit on a Mac. Updates for Macs remove malware, including rootkits, in addition to adding new functionality. Apple has security safeguards that guard against malware built right in. Nevertheless, there are no known rootkit detectors for macOS, thus you should reinstall macOS if you think your device may be infected. The majority of applications and rootkits on your computer are eliminated by doing this. As mentioned above, if the rootkit has corrupted the BIOS, it will need to be repaired; however, if the malware is still there, you might need to purchase a new device.
Which Tools are used for Rootkit Removal?
Let's look a little more closely at each Anti-Rootkit program and see what it has to offer.
TDSSKiller: The Kaspersky Labs tool TDSSKiller was developed to get rid of the TDSS rootkit. Other names for this rootkit include Rootkit.Win32.TDSS, Tidserv, TDSServ, and Alureon. If another rootkit is found, TDSSKiller tries to remove it, including the ZeroAccess or ZeroAccess rootkit.
rkhunter: A Unix-based utility called
rkhunter(Rootkit Hunter) searches for rootkits, backdoors, and potential local vulnerabilities. It does this by comparing the SHA-1 hashes of critical files with those of known-good ones in internet databases, looking for rootkit default folders, incorrect permissions, hidden files, and suspicious strings in kernel modules, and performing particular checks for Linux and FreeBSD. Due to its presence in widely used operating systems,rkhunteris noteworthy. In order to make the tool portable, the Bourne shell was used in its development. It is compatible with nearly all UNIX-derived platforms.chkrootkit: A popular Unix-based software called
chkrootkit(Check Rootkit) was created to aid system administrators in checking their systems for known rootkits. It is a shell script that searches for signatures of essential system programs using thestringsandgrepcommands and compares the results of a traversal of the/procfilesystem with the output of theps(process status) command to check for differences. It performs all of its own instructions from a rescue disc (usually a live CD), or it can optionally utilize a different directory. These methods enablechkrootkitto have a little bit more faith in the commands it relies on. Every application that tries to identify compromises (like rootkits) has built-in constraints regarding its dependability.Malwarebytes Anti-Rootkit: A trustworthy and cost-free rootkit removal tool called Malwarebytes Anti-Rootkit helps shield your computer from rootkits and other types of malware. It includes an intuitive wizard interface that makes it simple to swiftly check your machine for rootkits. The system area, sectors, and drivers are all places where rootkit malware tries to infect computers by default. Its database should be checked before you start scanning. It is portable, so you may use a flash drive to access it.
Bitdefender Rootkit Remover: A free and straightforward tool to check your computer for rootkits is called Bitdefender Rootkit Remover. It may be launched from a CD or USB drive and features an intuitive user interface that makes it simple to use. The cost-free and user-friendly rootkit removal application is called Bitdefender Rootkit Remover. Both 32- and 64-bit operating systems are compatible with it. Run the lone executable after downloading it to your computer. Due to its compact size, scanning may begin with a single click.
Sophos Virus Removal Tool: An anti-rootkit tool called Sophos Virus Removal Tool enables you to find and get rid of viruses and rootkits. It performs well at finding rootkits and checks the hard drive, system memory, and application files, among other things. There are no substitutes for carrying out a complete system scan. Installing the application is not necessary. It is launched instantly from a CD/DVD or USB flash device. When the scan is complete, you can remove the software.
Norton Power Eraser: Normally, Symantec doesn't provide any of its tools for free. Even their backup disk, the Norton Bootable Recovery Tool, has to be activated with a working product key. Luckily goodness, there is a free utility called Norton Power Eraser that can find and remove malware that is deeply buried throughout the system. It is a single, roughly 3MB-sized portable executable file. The Rootkit scan option is turned on by default in Settings, however, it cannot be used until after a restart.
Vba32 AntiRootkit: A portable, free, and simple-to-use rootkit revealer is Vba32 AntiRootkit. It analyzes your PC for any potential irregularities. It is a little program that is used with a USB mass storage device. Running this software requires administrator privileges. It checks for different kinds of hooks, drivers, processes, auto-run objects, etc., and then provides you with the information at the conclusion of the scan.
GMER: Another excellent option is GMER, which easily exceeds all other tools. The one drawback of this program is that it does take some level of understanding to evaluate the outcomes. This is not a gadget you can just click and disinfect. You run the tool's scan, examine the results, and determine what has to be fixed or eliminated. For dealing with more difficult illnesses, GMER is the instrument you need to have in your toolbox.
