Which of the following types of malware is designed to gain administrative-level control of a system?

The type of malware specifically designed to gain administrative-level control of a system is a rootkit. Rootkits are particularly stealthy and can operate at a low level within the operating system, allowing them to hide their presence and maintain access to the system without being detected. Once installed, a rootkit can enable an attacker to execute commands, access sensitive data, and manipulate system files and processes with elevated privileges. This makes rootkits especially dangerous because they can modify the operating system itself to conceal their activities and persist through reboots.

In contrast, ransomware is designed to encrypt files and demand a ransom for their recovery; it does not necessarily provide administrative control. Keyloggers are aimed at capturing keystrokes to steal sensitive information such as passwords and credit card numbers, but they do not control systems at an administrative level. Spyware primarily focuses on collecting information about a user’s activities without their knowledge and does not inherently provide administrative control over the system. This distinction clarifies why the rootkit is the correct answer when it comes to gaining administrative-level access.