### Comment:
How can malware be hidden on a computer system?

### REPLY:
To hide malware on a computer system, one can use advanced techniques such as rootkits. Rootkits are malicious software that are designed to conceal the existence of certain processes or programs from normal methods of detection. They can modify system files or kernel components to hide their presence, making it extremely difficult to detect and remove them. Another method is to use fileless malware, which resides in the memory or registry instead of being stored as a file on the computer's hard drive. This makes it harder for antivirus software to detect and remove the malware.