What is a Rootkit and How to Detect It?

Imagine dangerous thieves entering your office, and you can’t spot them! You’ll never know if they’re stealing your company’s crucial and secret data. Wouldn’t it be scary to know that your working procedures are vulnerable and your reputation is jeopardized? 

This can also happen in the digital world, and that’s why we’re talking about one such cyberattack method today: A rootkit attack. Keep reading to find out what it is, ways to spot it, and prevention and removal methods.

What is a Rootkit?

Let’s begin by understanding what a rootkit attack is. A rootkit is a type of malicious software cybercriminals use to gain control over a system, including hardware and firmware. 

Once executed, a rootkit allows hackers to steal, modify, or intercept data, use your system as part of a botnet or Distributed-Denial-of-Service (DDoS) attack, and install other malware.

A rootkit attack is difficult to spot when it’s active. It can also deceive antivirus and other security programs, allowing hackers to steal and intercept sensitive details without the victim’s knowledge. 

However, rootkits are also used by law enforcement agencies for examining computers, mobile phones, tablets, etc. Veriato is one of the common examples of rootkits used for a legitimate purpose. It helps companies monitor employees’ productivity through graphical representations illustrating productive and idle time.

How Does a Rootkit Work?

A rootkit takes over the operating system, which means it can target any device with an OS, and even entire networks. While rootkits are commonly referred to as a single piece of software, they usually consist of various tools that give perpetrators administrator privileges. 

Rootkits usually enter a system via phishing emails or social engineering tactics where users are directed to click or download a malicious link. Once downloaded, the rootkit conceals itself before activating to wreak havoc on your system. 

In many real-life examples of rootkit attacks, the malware enters by exploiting an unpatched software or operating system vulnerability. A rootkit can also be combined with other malware like trojans and viruses to hide its existence and bypass security protocols. In some cases, it disables or uninstalls antivirus and other security programs.

A rootkit can also be combined with keyloggers to record your keystrokes and obtain sensitive information, including login credentials and banking details. 

Rootkit Examples

In 2020, Flame, a rootkit also called Flamer, SkyWIper, and Skywiper was found. It infects systems to gain control over Microsoft Windows operating systems and uses keyloggers to attempt password attacks

Although experts couldn’t locate the hackers, they discovered that attackers used 80 servers spread across three continents to attempt rootkit attacks.

Flame had initially attacked around 1,000 machines, including systems in many government agencies, educational institutions, and private individuals.

What are the Types of a Rootkit?

A successful rootkit attack can give attackers full access and control over your system and company data. They may use one of the six types of rootkits mentioned below. 

Hardware or Firmware Rootkit

As the name says, this rootkit gets installed on hardware devices and infects the hard drive, firmware, memory chips, wi-fi router, etc. It’s used to steal or modify data written on the disk. Hackers can track online activity and even record keystrokes. In 2008, some European credit card machines experienced a hardware rootkit attack where hackers used tactics to transfer credit card details through a phone network. 

Bootloader Rootkit

A bootloader is a tool that reloads an operating system every time you turn on a computer. So, if a bootloader rootkit installs, it alters the functioning of the original bootloader, which consequently hits the operating system. 

Memory Rootkit

A memory rootkit attack doesn’t last long as the rootkit conceals itself in the computer’s RAM. It usually disappears upon rebooting a system as no permanent scripts are injected.

Application Rootkit

This is an example of rootkit attacks causing the most damage. An application rootkit deletes files on your system and replaces them with corrupted ones. You won’t be able to detect rootkit malware as the infected programs (usually MS Office) work without showing any traces. 

Kernel Mode Rootkit

Kernel-mode rootkits add or replace portions of code in the core operating system. It has unrestricted security access, but it’s difficult to write. Codes can get infected by bugs if miswritten, making rootkit detection easier.

Virtual Rootkit

A virtual rootkit gets embedded beneath the operting system, hosting it as a software-based virtual machine. As such, it can intercept and modify commands coming from the original OS. It’s extremely hard to detect as no code is injected at the kernel level.

How to Spot a Rootkit?

So, how do you know if you have a rootkit? Well, no commercial software claims 100% success in rootkit attack detection, as they’re good at concealing their presence. So, the best way is to run a rootkit scan that looks for signatures.

You can also look out for the following unusual computer behaviors:

  • Frequent error messages or blue screens.
  • Your browser redirecting to corrupted websites.
  • Slow and sluggish computer speed.
  • Changed screensaver and taskbar settings.
  • Incorrect date and time on your computer.
  • Unfamiliar extensions and plugins in your browser.

How to Prevent a Rootkit?

Since it’s challenging to find rootkits on networks and devices, companies must educate their employees on how to prevent rootkits attacks by taking care of the following measures.

Never Ignore Updates

It’s tempting to click on ‘remind later’ when an update notification pops up, but it can be harmful. Newer versions of programs and operating systems have better codes that can combat new techniques of cyberattacks. 

Avoid Opening Phishing Emails

Phishing emails carry malicious links or attachments that can help hackers access your system. Some common signs of phishing emails are:

  • Grammatical errors.
  • Unprofessional or low-quality graphics.
  • Creating a sense of urgency with words like, “ASAP,” “take quick action,” “reply immediately,” etc.
  • Unusual requests, especially asking for login credentials or bank details.
  • The domain name of the sender’s email address has inconsistencies or spelling errors.
  • Receiving unrequested or unfamiliar links or attachments.

Be Careful with Drive-by Downloads

Drive-by downloads are scary as they can automatically install rootkit software on your device when visiting a corrupted website. These days, threat actors have also sought ways to embed evil scripts into legitimate websites. 

Use Security Programs

Using a credible antivirus and firewall can help in rootkit attack detection and prevention. In addition, they’ll avert the entry of malware like viruses, adware, spyware, etc.

Don’t Download Links from Illegitimate Sources

Always download software and other files from an official source. You may find many websites selling them for free, however, they can be riddled with malicious scripts.

How to Remove a Rootkit?

Rootkit removal can be done by running a scan. But if it’s severely infected, you’ll have to uninstall your operating system using an external media device. 

You should stop using the infected computer if the issue persists. Mac owners must keep the macOS updated as Apple has security features that are quite efficient in preventing malware in the first place.

Final Thoughts

Rootkits are very challenging to detect, prevent, and remove as they’re often disguised.. Phishing and social engineering are common vectors of entry. So, you must avoid clicking phishing emails and downloading files from untrusted sources. Additionally, business owners should educate their employees to keep systems updated and be careful with drive-by downloads to prevent rootkit attacks.

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