Trojan horses are primarily known for causing what?

Trojan horses are primarily associated with data theft and loss because they are designed to deceive users into believing they are downloading a legitimate program, while their actual purpose is malicious. Once a Trojan horse is installed on a device, it can create vulnerabilities that allow cybercriminals to access sensitive information, steal data, or even compromise the user's entire system. This means that users can suffer significant consequences, including financial loss, identity theft, and damage to their devices or networks.

Unlike the other choices, which either describe benign functions or are unrelated to the typical malicious actions associated with Trojan horses, the primary function of these malware is indeed to facilitate unauthorized access to personal and sensitive data. This highlights the importance of cybersecurity awareness and vigilance when downloading and installing software.