A fileless attack exploits existing software, applications, and protocols to perform malicious activities. Threat actors use fileless attacks to gain control of targets without relying on executable files as the first phase of the attack.
During fileless attacks, threat actors infiltrate, take control, and perform malicious activities by exploiting vulnerable software that an end user might use daily, such as Microsoft Word or the Chrome browser, or software already deployed on a server.
Threat actors also use vulnerabilities to gain access to native operating system tools like PowerShell or any application that can allow a high level of access and privileges. These tools enable actors to perform basic commands across a network.
Fileless attacks are becoming increasingly common because traditional antivirus (AV) tools are not made to detect and prevent non-malware attacks. As a result, threat actors can use a fileless attack as a point of entry that might go completely overlooked, unless more advanced security tools are in place.