There are numerous sophisticated kinds of spyware used by intelligence agencies. Some of these consist of keyloggers, which record every keystroke made by a user; remote access tools, which permit an enemy to acquire control of a victim's device; and malware that is developed to steal delicate data or passwords.
see this One especially sophisticated kind of spyware is called a rootkit. Rootkits are designed to conceal themselves from detection, and can be really challenging to remove as soon as they have actually been set up on a system. They are typically utilized to offer an aggressor full control of a victim's maker, permitting them to spy on the user, and even take control of the device from another location.
Another advanced type of spyware is known as a botnet. They can also be used to spy on users, or to take delicate information.
Spyware is becoming increasingly sophisticated, and intelligence firms are constantly progressing their tools and techniques to keep up with the current dangers.