What is Fileless Malware

March 19, 2020 By Nick Anderson No Comments 5 minutes

The cyber-threats known as malware which continues to take various nefarious forms. One of such is Fileless Malware. It is a relatively new threat, but one that is lethal because it escapes detection. How exactly? Read on to learn more.

Note: Malware attacks are a significant cyber threat that you can avoid by connecting to a reliable VPN, like the FastestVPN. Doing so not only changes your virtual location, but guarantee cybersecurity with features like AES 256-bit encryption, robust encryption protocols and much more.

What Is Fileless Malware

What is fileless malware definition? It occurs when a malicious code enters into the computer’s memory rather than the hard drive. As the name indicates, it’s called “fileless” because this malware doesn’t download any files. Meaning, there’s no evidence for you to detect malware on your device.

While an anti-virus might be the common resort for malware or virus removal, that won’t always work for removing fileless malware, since there’s no file that the scanner can detect and remove. Moreover, file-less malware attacks directly affect your device and result in various symptoms, but the antivirus software won’t be able to detect the cause.  Comprehensively, here’s a recapitulation of what is fileless malware:

• Affects the memory instead of the hard drive
• No malware file
• Avoids antivirus software
• Leaves little evidence

How Does Fileless Malware Work?

Fileless malware attacks are quite disguised, but how do they work? First, the malware directly enters the computer’s memory and not the hard drive, escaping the primary mouse trap.

However, it gets into your device like other malware types, like the Trojan malware and others.

1. Social Engineering Tactics: The black hats leverage social engineering, prompting you to click on a link or an attachment, leading to unintended malware installation. A fileless malware attack primarily aims to access your sensitive information, like financial data. Or, it might disrupt an organizational operation.

2. Disguised as trusted device apps: Fileless malware disguises itself as reliable applications, such as the PowerShell or the Windows scripts, often bypassing security measures. Instead of being a separate file, it infects existing programs, making it harder to detect.

3. Command line alteration: Moreover, a file-less malware attack alters the computer’s command lines to enter the device. Meaning, detecting it can be a head-scratcher. And since it’s hard to detect, it does ample damage before you find it out.

Types of Fileless Malware

There are various types of fileless malware. However, they all branch out of 2 primary types: Windows registry manipulation and Memory code injection.

1. Windows Registry Manipulation

The malicious actor uses a link or a file for the user to click on, resulting in the Windows process writing and executing the file-less malware code in the device’s registry. Since there’s a manipulated command code, it’s hard to detect the malware via any antivirus software.

2. Memory Code Injection

File-less malware hides its malicious code within the memory of reliable applications, often those critical to essential system functions, such as the PowerShell. The malware operates within these authorized processes, exploiting vulnerabilities in common programs like the web browsers.

Mostly, the black hats leverage phishing campaigns to infect your computer with malware. Once inside the system, the malware executes directly from the computer’s memory rather than through an app specifically created by the attacker.

What Is an Example of Fileless Malware?

There are various fileless malware examples. Here are 3 famous fileless malware examples:

1. Number of Beast

This runs directly from the memory than files stored in the computer’s hardware

2. Frodo

Created in 1989, Frodo modifies device information and makes it look as if the file is uninfected even when this file-less malware is present.

3. Duqu

Being one of the crucial fileless malware examples, this memory-only malware is mostly used for industrial control. It uses 54×54 pixel JPEG files to communicate data from the command to control center.

What Are the Fileless Malware Symptoms

While detecting a fileless malware attack is challenging, you can leverage the following tips to help you detect the presence of this malware on your device:

1. Compromised System Memory: Look for changes in the processing within the System memory.
2. Unusual Device Activity: Look for indicators of Attack (IOAs) to detect any unexpected changes in your device activity, such as high memory usage or unauthorized scripting languages.
3. Alterations in system configuration: Check for alterations in the system’s configurations.
4. Abnormal Network Traffic: Look for abnormal network traffic on your device, like your computer connecting to botnet servers.
5. Different User Privileges: Keep a check on the application permissions and privileges to see if there are any administrator privileges without your knowledge.
6. Managed Threat Hunting: You can leverage managed threat hunting to expertly detect potential threats which you may not find through an antivirus software.

How to Prevent a Fileless Malware Attack

Here are the 3 common ways to prevent a fileless malware attack:

1. Don’t click on links that appear to be suspicious. Once you load that through your web browser and into your memory, it can inject itself in other processes.
2. Always install trusted programs and from trusted sources.
3. Read everything during the setup process for any other program that is trying to ask for installation. Always be careful when clicking “Next” on every screen.

Wrapping Up

As per the fileless malware definition, these fileless malware attacks can be hard to detect since there’s no file in the hard disk. However, symptoms like alterations in device activity can help you detect the malware.

Despite it being without a file, as per the fileless malware examples, they work similar to any other basic malware attack. They come from social engineering tactics where you click on a link, and your device is malware-infected.

However, you can mitigate these fileless malware attacks by connecting to FastestVPN. Along with guaranteed digital anonymity, you also leverage premium features which make cyber threats a tale of the past.

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