Which of the following is the MOST likely cause of this issue?

A security analyst reviews SIEM logs and detects a well-known malicious executable running in a Windows machine. The up-to-date antivirus cannot detect the malicious executable.

Which of the following is the MOST likely cause of this issue?
A . The malware is being executed with administrative privileges.
B . The antivirus does not have the mltware’s signature.
C . The malware detects and prevents its own execution in a virtual environment.
D . The malware is fileless and exists only in physical memory.

Answer: D