Fileless malware is a type of cyber attack that does not rely on the traditional method of installing malicious software on a victim's computer. Instead, it uses legitimate system tools and functions to carry out malicious actions, making it difficult to detect and prevent.
Fileless malware attacks often start with a phishing email or other social engineering technique that tricks the victim into clicking on a malicious link or opening a malicious attachment. This can trigger a series of events that ultimately lead to the execution of the fileless malware.
One standard method fileless malware uses is to leverage Windows Management Instrumentation (WMI) or PowerShell to execute malicious code in memory. These tools are legitimate built-in functions of the Windows operating system and are often used for system administration and automation tasks. By using these tools, the fileless malware can avoid detection by traditional security software that is designed to look for malicious files on the system.
Another method used by fileless malware is to leverage the registry to execute malicious code. The registry is a system and application settings database stored on the computer. Fileless malware can modify the registry to add a new entry that points to the malicious code, which is then executed when the system or application reads the registry.
Fileless malware can also use legitimate third-party applications, such as web browsers or productivity software, to execute malicious code. For example, a fileless malware attack may use a browser plugin to inject malicious code into a legitimate website, executed when the victim visits the site.
Fileless malware can be difficult to detect and remove because it does not leave any trace of itself on the victim's computer. Traditional security software that is designed to scan for and remove malicious files will not be able to detect or remove fileless malware.
To defend against fileless malware attacks, it is essential to have a multi-layered approach to security that includes preventative measures, such as training employees to recognize phishing emails and other social engineering tactics, and detective measures, such as network monitoring and intrusion detection systems. It is also essential to keep all system and application software up to date with the latest security patches to prevent vulnerabilities from being exploited by fileless malware.
In conclusion, fileless malware is a cyber attack that uses legitimate system tools and functions to carry out malicious actions, making it difficult to detect and prevent. To defend against fileless malware attacks, it is crucial to have a multi-layered approach to security that includes preventative and detective measures and keeps all system and application software up to date with the latest security patches.
References:
Fileless Malware: Definition and Examples (https://www.symantec.com/security-center/what-is/fileless-malware)
Fileless Malware Attacks: What You Need to Know (https://www.darkreading.com/threat-intelligence/fileless-malware-attacks-what-you-need-to-know/a/d-id/1332246)
Fileless Malware: A New Threat to Your Security (https://www.trendmicro.com/vinfo/us/security/definition/fileless-malware)
