Of the options presented for this problem, the most probable and the most likely answer to be the correct one would be the first option which is spyware.
Spyware installs itself on a computer without the user's knowledge or permission for the purpose of tracking the user's behavior. The spyware also is a software installed, sometimes it is installed erroneously since the objective would just for it to be downloaded in the computer, and tracks down all the pressed keys as an attempt to records passwords, usernames, and other important matters.
