Rootkit

What is Rootkit?

A rootkit is a type of malicious software designed to gain unauthorized access to a computer system, often by exploiting vulnerabilities or by tricking users into installing it. Once installed, a rootkit can conceal its presence and control over the system, allowing attackers to execute commands, steal data, or maintain persistent access without detection. Rootkits can be particularly dangerous because they operate at the root level of the operating system, making them difficult to detect and remove using traditional antivirus or security measures. Detecting and removing rootkits typically requires specialized tools and expertise, often aided by comprehensive IT asset discovery tools to identify the presence of malicious software.

Where did the term rootkit come from?

You can split the word rootkit into two to understand its etymology. “Root” refers to the root user of an account—the administrator with the highest level of privileges—and “kit” refers to the tools that enable access. Originally, the term rootkit didn’t carry negative connotations; it simply referred to tools that allowed administrators to access a system or network. However, today, rootkit is strongly associated with malware and malicious intent. It usually refers to malware that is difficult to detect using system tools or by users.

What kinds of rootkits are there?

There are various types of rootkits, each using a different approach to achieve stealthy control over a machine, system, or network. For example:

• Hardware or firmware rootkits: These target components like your router and can be particularly difficult to detect.
• Bootloader rootkits: These compromise security at the point your OS is loaded.
• Application rootkits: These replace specific applications, such as Excel or Notepad, with malicious versions that look legitimate. Advanced antivirus tools can identify these malicious programs.
• Kernel mode rootkits: Operating at the kernel level, these are the most dangerous. They can alter system configurations and OS settings, attacking the core of your operating system.
• Virtual rootkits: These host the operating system as a virtual machine, often in the cloud, making them extremely hard to detect.

We love this graphic from Bitdefender that visualizes the severity levels of rootkits and their malicious purposes.

What can attackers use rootkits for?

You can think of a rootkit as an invisibility cloak that hides the behavior of attackers. With a rootkit in place, bad actors can:

• Inject malware: A rootkit enables attackers to install malicious software, including viruses, worms, ransomware, or spyware. This malware is hard to detect, especially if it’s used for activities like crypto mining. A rootkit can also create persistent backdoors, enabling attackers to access systems repeatedly.
• Gain remote access: Remote access scams are growing in popularity. Attackers can steal sensitive data or disrupt operations, often initiating with fake malware warnings that trick users into granting deeper access.
• Change security settings: Rootkits can modify security settings or system configurations, making it harder for IT teams to detect or remove the rootkit. While rootkits don’t escalate privileges themselves, they provide malicious users with unauthorized access.
• Steal data: Attackers can execute commands to steal or delete sensitive files. Some rootkits, called payload rootkits, are designed to log keystrokes and steal credentials.
• Compromise privacy: Rootkits can expose you to significant fines and reputational damage by enabling attackers to sell sensitive data, compromising compliance efforts.

How can you detect a rootkit attack?

Rootkit attacks are notoriously hard to detect, but there are warning signs, such as:

• Suspicious activity: Changes to Windows settings, such as background images or start menu items, without your authorization.
• Performance issues: A sudden slowdown in system performance could indicate rootkit infection.
• Critical failures: Loss of control over your keyboard, mouse, or other peripherals, or being locked out of your computer, might signal a rootkit attack.

How can you protect against rootkit attacks?

• Invest in robust cybersecurity solutions: Atera integrates with Bitdefender, which offers advanced anti-rootkit solutions, and Webroot.
• Maintain a rigorous patch management schedule: Keeping software and hardware updated reduces vulnerabilities. Monitor system performance to detect anomalies early.
• Establishing performance baselines can help identify irregularities that could signal a rootkit.
• Educate clients: Awareness is key. Train your clients to recognize suspicious activity and report unusual behavior immediately. Sharing resources like this article is a great place to start!