What purpose does Spyware serve in a system?

Spyware primarily serves to collect information about system use, which encompasses a wide array of activities. This can include gathering data on user behavior, software usage, and system configurations without the user’s consent. The information collected can be utilized by malicious actors for various purposes, such as creating targeted advertisements, stealing personal information, or other cybercriminal activities.

While logging all keystrokes is indeed a function associated with a specific type of spyware called a keylogger, it is just one aspect of what spyware can do. Spyware is broader in scope, involving passive data collection rather than solely focusing on keystroke recording.

The other options define characteristics of different types of malicious software. Encrypting files for ransom is a hallmark of ransomware, while providing unauthorized access characterizes backdoors or certain types of trojans. Collectively, these distinctions underline that spyware's main function is to silently gather information without alerting the user, which is why the focus is on its role in collecting data about system use.