Keyloggers, also referred to as system monitors, are applications designed to capture computer activity, including keystrokes, websites visited, search history, email discussions, chatroom dialogue, and system credentials. They typically collect screenshots of the current window at scheduled intervals.
Keyloggers may also collect functionality, allowing for stealthy capture and transmission of images and audio/video from any connected devices. They might even allow attackers to collect documents that are printed on connected printers, which can then be transmitted to a remote server, or stored locally for retrieval.