What type of malware is known for stealing confidential data and collecting user information?

The type of malware primarily known for stealing confidential data and collecting user information is spyware. This form of malware operates covertly by monitoring user activities, gathering sensitive information such as passwords, credit card numbers, and personal details, and then transmitting this data to the malware's creator.

Spyware often infiltrates systems through various means, such as bundled software downloads or as a result of security vulnerabilities in applications and operating systems. Unlike adware, which is primarily aimed at displaying unwanted advertisements, or ransomware, which encrypts files and demands a ransom, spyware focuses specifically on data collection without the user's consent.

Mobile malware could refer to various types of malicious software targeting mobile devices, but it doesn't exclusively pertain to data-stealing. Ransomware and spyware serve very different purposes; ransomware locks files and demands payment for their release, whereas spyware is about capturing information silently. Thus, spyware is the most accurate classification for the malware that steals confidential data and gathers user information.