Personal users and enterprises alike should take all types of computer viruses and malware very seriously. But of all malware threats today, rootkits might be the most hazardous. This is not only because they can cause extensive damage but also because they can be very difficult to find and remove.
The word “rootkit” is derived from the Unix concept of root access, which allows the user the broadest, most privileged access to a system. Someone with root access can alter a system’s settings and files. The malicious applications the rootkit contains are referred to as the kit.
This article will dive into what rootkits are, what they are capable of, and how they hide themselves on a device. Then we’ll discuss how they can be removed and the measures you can take to protect yourself from these malicious hacker tools.
What Are Rootkits, and What Makes Them Dangerous?
Rootkits allow cybercriminals to operate your computer remotely and can include several different tools. They may let hackers steal passwords or financial information. They may install keyloggers that track your keystrokes, making it easy for attackers to collect personal data. Rootkits can also disable your security software so your system can’t find or remove them.
Once a rootkit gains unauthorized access to a computer, it can install other malware to make your computer part of another attack, such as a botnet or Distributed Denial of Service (DDoS) attack. And because any device that uses an operating system can be targeted with a rootkit, this is likely to become a bigger problem as the Internet of Things (IoT) continues to grow.
Another reason why rootkits are so detrimental is because they are designed to run close to or within the operating system’s kernel, where they are difficult to see. This allows them to effectively masquerade as part of the operating system so they can launch commands. Because they are so difficult to identify, they can remain on a device for a while, causing more and more damage.
How Are Rootkits Installed?
Rootkits may be installed on a target device in a number of different ways.
Social Engineering Through phishing or other types of social engineering, rootkit victims can unknowingly install or download a rootkit that conceals itself within other processes. (Multi-factor authorization (MFA) is one reliable way to guard against social engineering.)
Vulnerability Exploitation If a software program or operating system on your computer has an unpatched weakness or hasn’t installed the latest security updates, the resulting vulnerability can allow hackers to force a rootkit onto that device.
Infected Files Rootkits and other malware are sometimes bundled with other files that seem legitimate, such as PDF downloads. They may also be attached to pirated media or illicit third-party app providers.
Drive-by Downloads This when a website automatically installs malware on a device without you having to click on anything or interact with the site at all. This can come from malicious websites or from legitimate sites that are vulnerable to the injection of malicious code.
Types Types of Rootkits
There are several different types of rootkits that behave somewhat differently.
These rootkits may be installed on your hard drive, router, or system BIOS. Rather than manipulating your operating system the way other malware might do, hardware or firmware rootkits will target your device’s firmware and install malware that flies under the radar of antivirus software.
Since this type of rootkit affects your hardware, it is capable of logging keystrokes and tracking your online activities to steal private information.
Memory rootkits are embedded in your device’s random access memory (RAM). They run in the background, executing their malicious behaviors and dragging down your computer’s performance.
The good news is that because memory rootkits are contained in RAM, they aren’t capable of inserting permanent code. Their lifespan usually comes to an end as soon as you reboot, although a bit of extra work may be required to eliminate them completely.
Your bootloader is just what it sounds like – the mechanism that loads your OS as soon as your computer is powered on. Bootloader rootkits replace your authorized bootloader with a malicious one.
If a rootkit is installed in your bootloader, it will be activated before your operating system (OS) is even fully loaded.
Kernel Mode Rootkit
These are some of the most dangerous rootkits because they compromise the core of your computer’s operating system at the kernel level. Via a kernel rootkit, hackers add their own code to subvert the legitimate code within the kernel, altering the function of your operating system.
Cybercriminals use these to access files on your hard drive, potentially stealing private data, such as financial documents.
Application rootkits replace legitimate program files with rootkit files, allowing them to change how standard applications behave. They may be injected into software you use every day, such as word processors, spreadsheets, or project management programs. Every time you start up the infected program, the attacker gains access to your computer.
The infected programs still appear to run normally, making application rootkits difficult to detect. But since they run at the application level, reliable antivirus programs can usually identify them.
Virtual rootkits can subvert your operating system without making any changes to the kernel. This is because they load themselves underneath the target OS and then host it as a virtual computer. Once a virtual rootkit is installed, it can hijack the hardware calls made by the original operating system.
How to Know if You Have a Rootkit
As stated before, rootkits can be very tricky to identify because they are inherently designed to stay hidden. The fact that they can disable security software makes them even more evasive. Instead of looking for the rootkit itself, it may be more useful to pay attention to how your device behaves so that you can pick up on any signs of a problem.
Here are a few clues about your device’s behavior that may indicate a possible rootkit infection.
Windows “blue screen of death” – You frequently experience the familiar white text on a blue screen, forcing you to reboot
Slow performance – Your device takes forever to boot, executes simple tasks slowly, freezes, or doesn’t respond to input
Unexpected browser behavior – You notice unfamiliar bookmarks, unrequested redirects, or other strange actions
Altered Windows settings – Taskbar behavior, screensaver, time/date, wallpaper or other settings change, but you didn’t change anything
Odd network functions – Web pages or other network activities are unreliable and may cut in and out
If you notice any of these behaviors, consider running a rootkit scan. Your antivirus software may be able to initiate this, but it’s best to power down the infected device and run the scan from a system you know is clean.
How to Remove a Rootkit
Rootkit removal is complex, usually requiring specific tools designed to get rid of them. To fully remove a rootkit from any device, it may be necessary to rebuild the device’s operating system from scratch or reformat the hard drive. In some cases, even that won’t completely eliminate the problem.
However, if you suspect you have a rootkit on your device, here are a couple of places to begin.
In a Windows Environment
Rootkit removal on a Windows device usually begins with a scan. If the rootkit is deeply embedded, it may be removed with a clean install of Windows. Using an external media for the installation is safer than using the Windows installer.
If the rootkit infected your BIOS, a professional repair will be required. If that doesn’t remove it, you may have no other options but to replace the computer.
In a Mac Environment
Apple systems have some built-in security features designed to protect you from malware. Start by running the latest OS update, because in addition to adding features, it can also remove malware, including rootkits.
However, MacOS does not feature specific mechanisms for rootkit detection, so if you think you might be infected with rootkits, reinstalling the OS should remove most of them. In the case of a rootkit in the BIOS, however, you’ll need a professional repair and possibly a new device.
How to Prevent Rootkits
The dangerous and evasive nature of rootkits makes prevention crucial. Consider implementing all of the following to mitigate your risk.
Stay Vigilant With Software Updates
Keeping your operating systems and software programs current with the latest updates is critical to patching weaknesses that may allow hackers to inject any kind of malware, including rootkits. In an enterprise environment, require updates to be made automatically or at regular intervals.
Avoid Phishing Scams
Phishing and other social engineering attacks are common methods hackers use to infect computers and enterprises with rootkits and other malicious attacks. Make sure everyone who uses your system is trained on how to recognize and avoid these scams, often executed via suspicious emails or fake links. Enact policies to keep suspicious emails from reaching your employees.
Be Careful With Downloads
Train your workforce to be sure any attachments they click on are from trusted senders and to avoid downloading any software from unfamiliar websites. If a web browser issues a warning about a site, all users should trust that warning and navigate away from the site before interacting with it.
Comprehensive Security Solutions
Consider adopting a complete security solution with best practices for identity verification (such as Zero Trust and Single Sign-On), fraud detection, multi-factor authentication (MFA), web/API access, and more. This can make protecting your enterprise from all kinds of threats effective and simple, without sacrificing user experience.
Ping Identity can help you provide every member of your organization with frictionless access that secures your workforce from threats. Download the ultimate guide at the link.
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