The correct answer islegitimate system processes executing encoded commands. Fileless malware avoids writing binaries to disk and instead abuses trusted processes such as PowerShell, WMI, or rundll32.

Encoded or obfuscated commands executed by legitimate binaries are a strong indicator offileless execution and defense evasion. Cisco Secure Endpoint provides deep visibility into command-line arguments and process behavior, enabling detection of this technique.

Option A is normal behavior. Option B may indicate suspicious execution but still involves files. Option D relies on file presence, which fileless attacks intentionally avoid.

This technique aligns withMITRE ATT&CK – Command and Scripting Interpreter and Defense Evasionand is directly relevant toCBRTHD exam objectivesrelated to endpoint-based threat hunting.

Therefore,Option Cis the correct answer.