Invisible Intruders: The Rise of Fileless Malware

Orhan Öztaş
3 min readMay 5, 2023

Fileless Malware: The Stealthy Threat That’s Hard to Detect

In the world of cybersecurity, malwares are permanently evolving. We will get the bottom of Filess Malware in this article. Let’s do this.

One such threat that has been gaining attantion in recent years is fileless malware. Unlike traditional malware that relies on files to infect a system, fileless malware operates without creating any files on the infected system, making it extremely difficult to detect and defend against.

Fileless malware attacks are typically executed through the system’s memory, which makes them highly stealthy and difficult to detect. Attackers can use various techniaues to deliver fileless malware, such as exploiting vulnerabilities in the system or using social engineering tactics to trick users into running malicious code.

One of the most significant advantages of fileless malware for attackers is that it can evade traditional antivirus and anti-malware tools that rely on scanning for malicious files. Since fileless malware doesn’t create any files on the infected system, these tools are unable to detect and prevent such attacks.

Another advantage of fileless malware for attackers is that it can often bypass security measures that are designed to prevent the execution of malicious files. For example, some security tools might block the execution of unknown or suspicious files, but they may not be able to detect fileless malware that is executed through legitimate system processess.

Fileless malware attacks can have devastating consequences, as they can be used to steal sensitive data, execute unauthorized commands, or spread further within the network. Since fileless malware is difficult to detect, it’s essential to have proper security measures in place to defend against such attacks.

To defend against fileless malware attacks, organizations can take several measures. One approach is to use behavior-based detection tools that can identify suspicious activity and abnormal behavior within the system’s memory. These tools can detect fileless malware attacks by analyzing the system’s behavior and identifying any malicious activities.

Another approach is to implement strict security policies that limit the execution of code from unknown or untrusted sources. Users can also be trained to recognize social engineering tactics and avoid running unknown code or opening suspicious email attachments.

  • Poweliks: Poweliks is a well-known fileless malware that spreads through spam emails and malicious websites. It uses a unique technique that involves hiding its code in the Windows Registry, which makes it difficult to detect and remove.
  • Kovter: Kovter is another type of fileless malware that is often distributed through malvertising campaigns. It operates by injecting its code into legitimate processes such as Explorer.exe, making it difficult to detect.
  • Emotet: Emotet is a sophisticated banking Trojan that uses a variety of techniques to evade detection, including fileless malware techniques. It typically spreads through spam emails and malicious attachments.
  • WMI Trojans: WMI Trojans are a type of fileless malware that uses Windows Management Instrumentation (WMI) to execute malicious code. These Trojans are difficult to detect and remove because they operate entirely in memory and do not leave any files on the system.
  • DNSMessenger: DNSMessenger is a type of fileless malware that uses DNS queries to communicate with its command and control server. This malware is difficult to detect because it does not leave any files on the infected system, and it uses legitimate network traffic to communicate with its command and control server.

These are just a few examples of fileless malware. As you can see, fileless malware is becoming increasingly common, and it poses a serious threat to organizations and individuals alike. It is important to stay vigilant and take appropriate security measures to protect against these types of threats.

In conclusion, fileless malware is a stealthy and sophisticated threat that can be difficult to detect and prevent. Organizations must implement comprehensive security measures to defend against fileless malware attacks and protect their sensitive data from being compromised.

By staying vigilant and adopting a proactive approach to cybersecurity, organizations can stay one step ahead of cybercr’minals and safeguard their digital assets.



Orhan Öztaş

Cyber Security Consultant. Writing articles for helping you about cyber security.