Cyber attackers resort to different methods every day; It is working to develop new attack methods in order to avoid detection by security systems. Ransom In addition to malicious files, which have become difficult to detect with the increase in software, fileless There is also a significant increase in malware campaigns carried out by.
It is possible to explain the increase in fileless attacks by several important reasons. In fileless attacks, the attacker can easily bypass static detection because he does not directly engage in memory activity on the targeted system. The process of detecting, analyzing and responding to fileless attacks is more complex. When this information is evaluated together, it is clear that the need for qualified personnel resources and advanced technologies will increase in order to resist such attacks.
Fileless attackIt can be defined as a method of attacking the disk on the targeted system without creating any malicious file software. However, this attack method varies depending on its purposes.
Some of those;
- Attack Without Having an Executable File Methodi: Attackers can create and run a file to access the targeted system. In fileless malware, attackers do not need a file. Executable files located on the main system of the targeted institution are actively used. When performing this operation, the attacker does not need a .exe file he created.
- Attack Management Using Multiple Access Points: Attackers try to take control of the system they target from many different points. In fileless malware attacks, attackers directly target management services. Thus, attackers can carry out their malicious activities by using services as well as files in the system. Examples of management systems include cloud structures, authentication mechanisms, data backup and recovery structures.
- Code Injection Management: It is a method based on placing dynamically defined code into the memory of a process. Malicious code executed during dynamic code injection does not require a standard memory size. The malicious piece of code disguises itself in this way.
Types of Fileless Attacks When examined, it is possible to draw a general picture. There are many Trusted structures and authorized applications for the institution. Examples of these include security solutions and authorized accounts. Fileless malware, on the other hand, directly targets not only standard users but also the security structures of the institution. After gaining access to the management and security services in the institution, built-in processes, registry, scripts, etc. It easily hides its own by using it. Since he acts like a standard user, it is not easy to detect his behavioral anomaly. Since the attacker does not perform any signature-based action during the self-authorization phase, it is very difficult for antivirus software to detect him/her.
As with every security approach, awareness should be provided against fileless attacks. Institutions should shape their security posture according to their employees, data and possible cyber actions. It must be ensured that the established principles are adhered to. Some security measures that should be implemented for fileless malware are as follows:
- Restrictions should be placed on scripts where the user can join another network within the organization. Scripts must be made available to be read only by other than authorized users. Authorized users should also have access to other machines as needed.
- Powershell is an important tool for attackers. All Powershell commands run within the organization must be monitored and detected. Attackers even need ordinary Powershell commands (hostname, ipconfig, etc.) during the discovery phase. Powershell poses a risk because fileless malware requires tools available in the system.
- Some PE(Portable Executable) and macro files are allowed for standard users. However, built-in files or file types that standard users will not need should not be allowed. Examples of this include psexec.exe or ssh.exe, which are used to access another computer remotely.
- Cyber attack methods are increasing and developing day by day. Therefore, security providers and software with security content frequently release updates to improve their security status. Making updates allows action to be taken at an early stage against possible cyber attacks.
Adhering to the items explained above fileless attacks It will have an important role in providing proactive defense against Fileless malware Understanding the actions of people using it will provide the most effective defense. .