Fileless Malware: The Secret Weapon of Cybercriminals That Targets Your System’s Vulnerabilities

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Fileless malware is a type of malicious software that does not rely on files to infect and compromise your system. Instead, it uses legitimate programs, applications, and protocols that are already built into your operating system, such as PowerShell, WMI, JavaScript, and Word. By exploiting these trusted tools, fileless malware can evade detection by traditional antivirus software and hide in your system's memory, registry, or cache.

Fileless malware can then perform various malicious activities, such as stealing your data, encrypting your files, spying on your activities, or launching ransomware attacks.

Fileless malware is not a new phenomenon, but it has become more prevalent and sophisticated in recent years. According to a report by Fortinet, malicious PowerShell scripts increased more than 1,000 percent in 2018 and accounted for 89 percent of fileless malware attacks. Fileless malware attacks are also more likely to succeed than file-based attacks, as they have a higher infection rate and a lower detection rate. According to a study by the Ponemon Institute, fileless attacks are ten times more likely to succeed than file-based attacks.

How does fileless malware work? Fileless malware can use different techniques to infiltrate and infect your system, but they generally follow a similar pattern:

• The attacker delivers the fileless malware payload through a phishing email, a malicious link, or a compromised website. The payload may be embedded in a document, an image, or a script.
• The user clicks on the malicious attachment or link, which triggers the execution of the fileless malware code in the system's memory. Alternatively, the attacker may exploit a vulnerability in the system or the browser to inject the code remotely.
• The fileless malware code then leverages a legitimate program or application, such as PowerShell, WMI, JavaScript, or Word, to run malicious commands or scripts. These commands or scripts may download additional payloads from the internet, modify the system's settings, access sensitive information, or launch other attacks.

• The fileless malware code may also persist in the system by hiding in the registry, the cache or other locations that are not scanned by antivirus software. This allows the fileless malware to remain undetected and active even after rebooting the system.

  
  

What are some examples of fileless malware attacks?

Fileless malware attacks have been used by various cybercriminals and threat actors for different purposes and targets. Some of the notable examples of fileless malware attacks are:

The Equation Group: This is a highly sophisticated and secretive group of hackers that is believed to be linked to the NSA. The Equation Group used fileless malware to infect thousands of computers around the world with spyware and backdoors. The fileless malware was delivered through USB drives and exploited vulnerabilities in hard drive firmware.

The Lazarus Group: This is a notorious group of hackers that is believed to be sponsored by North Korea. The Lazarus Group used fileless malware to launch several high-profile cyberattacks, such as the Sony Pictures hack in 2014, the Bangladesh Bank heist in 2016, and the WannaCry ransomware outbreak in 2017. The fileless malware was delivered through phishing emails and exploited vulnerabilities in Windows or Adobe Flash.

The FIN7 Group: This is a prolific group of cyber criminals that specializes in stealing credit card data from retail and hospitality businesses. The FIN7 Group used fileless malware to compromise hundreds of companies across the US and Europe. The fileless malware was delivered through phishing emails that contained malicious Word documents. The documents contained embedded macros that executed PowerShell scripts to download and run additional payloads.

How can you protect yourself from fileless malware attacks?

Fileless malware attacks are difficult to detect and prevent, but they are not impossible to stop. Here are some tips to help you protect yourself from fileless malware attacks:

• Keep your system and applications updated with the latest security patches and updates. This can help you prevent attackers from exploiting known vulnerabilities to inject fileless malware code into your system.
• Use reputable antivirus software that can detect and block fileless malware attacks. Some antivirus software can monitor your system's behavior and memory for any suspicious activity or anomalies. Some antivirus software can also scan your registry, cache, and other locations for any traces of fileless malware.
• Avoid clicking on suspicious links or attachments from unknown sources. This can help you avoid downloading or executing fileless malware payloads that may be embedded in documents, images, or scripts.
• Disable or restrict the use of programs or applications that are commonly used by fileless malware attacks, such as PowerShell, WMI, JavaScript, or Word macros. This can help you reduce the attack surface and prevent attackers from leveraging these tools to run malicious commands or scripts.
• Use strong passwords and encryption for your data and devices. This can help you prevent attackers from accessing your sensitive information or locking your files with ransomware.

In conclusion, Fileless malware is a serious and growing threat that targets your system's vulnerabilities and exploits your trust in legitimate programs and applications. Fileless malware can evade detection by traditional antivirus software and hide in your system's memory, registry, or cache. Fileless malware can then perform various malicious activities, such as stealing your data, encrypting your files, spying on your activities, or launching ransomware attacks. To protect yourself from fileless malware attacks, you need to keep your system and applications updated, use reputable antivirus software, avoid clicking on suspicious links or attachments, disable or restrict the use of programs or applications that are commonly used by fileless malware attacks, and use strong passwords and encryption for your data and devices. By following these tips, you can reduce the risk of falling victim to fileless malware attacks and keep your system and data safe.

By: Aleke Francis AO is a Cybersecurity expert, CyberThreat Intelligence Analyst, Researcher, and an InfoTech blogger. Team Lead InfoTech News Hauz