What is a Fileless Malware?

With the advancement in security, cybercriminals are inventing unique techniques to perform malicious tasks. One such unique threat is Fileless Malware.

Let us discover what this Fileless malware is, how it gets entry into a system, why can't security programs detect it, and some measures to prevent it.

What is a Fileless Malware?

Fileless malware is a unique type of malicious program whose attacking technique is entirely different from the regular malware programs. Generally, cybercriminals introduce malware files into the device to infect it. Over the years, malicious programs like Trojans, Spyware, Ransomware, and others have created havoc by getting into the system through a file or app. However, this does not apply to Fileless malware.

A Fileless malware would sneakily activate itself in the files and applications that are already present on your operating system. It can infiltrate your system without any malicious application being installed or any file downloaded. Since it uses the already present tools on the device, the attack would look like a normal running process making the Fileless malware hard to spot. No antivirus has Fileless malware's signature as it leaves no traces on the hard drive.

On a Windows OS, a typical Fileless malware usually targets the programs like Windows PowerShell. Using Fileless malware, the attacker can control such services and execute the commands to harm the computer without involving any malicious files or codes.

How does Fileless Malware infiltrate your system?

Since Fileless malware programs do not require any medium like a rogue application or file to enter the system, how does it infect any device!.

Here are the few ways Fileless malware gets activated on your system −

  • Through Phishing Emails or Pop-ups. When you click the infected link of a fake email or pop-up, it can directly load into the memory of the system and enable the hackers to use the shell scripts to perform malicious tasks like stealing your confidential information.

  • Malicious codes can be injected into already installed legitimate applications. Cyberattackers can use different tricks to inject malicious codes into your trusted applications, like Microsoft Word or similar.

Why can't Security Programs detect Fileless malware

To get the answer to this question, first, you have to know the working of a typical antimalware program. An antimalware program generally detects a potential threat by matching its signature by the signature presents on its Virus definition database. If the signature matches, then the file or app is considered a threat. Many antimalware programs also use pattern recognition. In this, the pattern of a malware attack is stored and matched with any potential incoming threat.

The problem with Fileless malware is, it attacks without any file or application. Since there is nothing to detect, a traditional antimalware program is unable to catch the Fileless malware. The Fileless malware does not write itself on the hard disk; instead, it directly attacks the RAM - Random Access Memory of the system without leaving any traces behind, thereby deceiving the antimalware programs.

How to stay protected from Fileless Malware

Since there is no dedicated security application to detect Filesless malware, it isn't easy to stay protected from it. However, if you follow these preventive tips, Fileless malware won't be trouble −

  • Generally, Fileless malware takes advantage of outdated operating systems and application vulnerabilities. It is therefore recommended always to keep your system and applications updated with the latest version.

  • When installing an application, always check what permission you are providing to it.

  • Always download the software for your computer from the trusted sources.

  • Opening a link to an unknown email can lead to a phishing attack introducing the Fileless malware in the system.