Mark Sheldon Villanueva

By: Mark Sheldon Villanueva on November 5th, 2024

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How to Protect Your Business from Fileless Malware

Cybersecurity

Securing your personal and professional data is critical for any business, regardless of size. Unfortunately, there are invisible threats that could be waiting to strike. One of them is fileless malware.

Unlike traditional malware, fileless malware doesn’t need to be installed on a target’s system. Instead, it operates in your computer’s memory, exploiting legitimate programs to carry out its malicious activities. That makes it significantly harder to detect and remove.

The question now is how can you protect your business from a threat that can evade traditional detection methods? We can help with that.

Intelligent Technical Solutions (ITS) is an IT service company that with years of experience providing businesses with advanced cybersecurity services. In this article, we’ll arm you with the knowledge to protect your business from fileless malware threats.

Understanding Fileless Malware 

Fileless malware is a sophisticated cybersecurity threat that bypasses conventional detection methods used by many antivirus programs. Unlike traditional malware, which relies on files stored on a device’s hard drive, it operates directly within your computer’s memory. It exploits existing legitimate system tools and applications, making them harder to detect. 

If you want to protect yourself from this threat, you need to understand the different types, how they’re deployed, and the risks they pose. 

Types of Fileless Malware 

Fileless malware can be categorized based on its behavior and attack techniques: 

1. Memory-Only Malware

This type exploits applications already installed on the computer or runs directly in the system’s RAM. It hijacks those legitimate processes to inject malicious code into your system’s memory.

To give you a better idea of how that looks, imagine opening a web browser and unwittingly executing the malicious code. It leaves no trace on the hard drive and disappears once the device is rebooted. That may sound innocuous, but don’t be fooled. It can cause significant damage or data loss during its active period. It can capture keystrokes, steal passwords, or redirect users to malicious sites, all without creating or altering files on the hard drive. 

2. Registry-Based Malware

Instead of files, this type uses the Windows Registry to execute malicious code. It will embed itself in the registry and persist even after rebooting the system. The malware will then write a script into the registry that is executed every time the computer starts. Once it does, it can download more malicious payloads or enable unauthorized remote access. 

3. Script-Based Malware

This malware performs its malicious activities by running scripts that appear harmless. It uses common scripting languages that are part of standard operating systems, like PowerShell or JavaScript. It’s usually delivered through a phishing email. Once a user clicks the malicious link, the script will run and reach out to an external server. It will then download and execute further malicious commands directly in the system’s memory. 

phishing scam

Risks Posed by Fileless Malware 

The risks associated with fileless malware are considerable due to how difficult it is to detect and remove. 

1. Evasion of Detection

Traditional antivirus software scans files and directories for known threats. However, fileless malware leaves no files to scan, allowing it to operate undetected. 

2. High Success Rate

Fileless malware leverages trusted system tools and processes. Because of that, it typically encounters fewer barriers to execution. That makes it more likely to succeed in its objectives. 

3. Persistence and Stealth

Some fileless malware can embed malicious code in the system registry or scheduling tasks. That allows them to persist and remain active even after the system restarts. 

4. Potential for Significant Damage

Fileless malware can perform a variety of harmful actions. They can steal sensitive information or install even more malicious payloads into your system. That can compromise personal, financial, or business data. 

User receiving a fileless malware alert on a mobile device, highlighting cybersecurity risks

Practical Steps to Prevent Fileless Malware 

Here are the best ways to protect yourself from fileless malware:

1. Update and Patch Regularly

Ensure that your systems and applications are up to date with the latest patches and updates. These updates can fix vulnerabilities that could be exploited by malware. That closes security gaps, making it harder for fileless malware to find a foothold. 

2. Enhance Email Security

Phishing emails are one of the most common entry points for fileless malware. That’s why it’s vital to strengthen your email security. Use tools that scan and filter emails for suspicious links and attachments. In addition, educate yourself and your colleagues about the dangers of unsolicited emails. Teach them the importance of not clicking on unknown links or downloading attachments from untrusted sources. 

3. Utilize Behavior-based Detection Tools

Fileless malware does not leave typical malware footprints. That’s why it’s better to use security solutions that detect suspicious behavior instead. These tools monitor the system for unusual activities, such as unexpected scripts or unusually high CPU usage. Those might indicate the presence of malware operating in your system’s memory. 

4. Restrict Administrative Privileges

Limit the use of administrative privileges on your computer. Fileless malware often needs administrative access to exploit system tools effectively. If you restrict these privileges, you can reduce the malware’s ability to execute its activities even if it does manage to penetrate your system. 

5. Harden Your Endpoints

Strengthen the security of your endpoints - the devices that connect to your network like computers and smartphones. Employ application whitelisting, which allows only pre-approved programs to run. That can prevent unauthorized use of system utilities by fileless malware. Additionally, consider disabling scripts and macros in applications where they are not necessary. 

6. Get Help from Experts

Some MSPs offer managed cybersecurity services that can secure your entire IT environment. They can help you implement every item on this list to prevent and mitigate fileless malware attacks. Not to mention, they can also offer security information and event management (SIEM) solutions, which help in early detection and prevention. 

Cybersecurity measures on a laptop screen to defend against fileless malware attacks

Need Help Protecting Your Business from Fileless Malware? 

The stealthy nature of fileless malware makes it a difficult challenge in the realm of cybersecurity. However, by implementing the practical steps covered in this article, you can mitigate the risk of a fileless malware infection. 

Remember that you don’t need to take on the challenge of fileless malware alone. If you need help, our team at ITS is ready to provide support. Our ITS Secure package offers advanced cybersecurity solutions, including SIEM solutions that can help you prevent all kinds of attacks, even the ones that can evade traditional detection methods. Schedule a meeting with our experts to get started, or read through our Learning Center resources: