An 'idle' system is also referred to as what?

• A. PC not connected to the Internet
• B. PC not being used
• C. Zombie
• D. Bot

Answer: (C)

In botnet terminology, an idle system is a computer that has been compromised and is under the attacker’s remote control, but is not actively performing tasks until commanded. This kind of host is commonly described as a zombie, since it lies dormant while still being controlled to carry out malicious activities like sending spam or participating in coordinated attacks. The term bot refers to the software that runs on such machines, not the host itself, so the idle, compromised machine is best called a zombie. The other options describe normal or unrelated states (offline, simply idle, or the software rather than the host), which don’t capture the idea of a compromised, under-control machine.