Which term describes the malicious software designed specifically to exploit unreported vulnerabilities?

The term that describes malicious software created to exploit unreported vulnerabilities is a zero-day exploit. A zero-day exploit takes advantage of vulnerabilities in software that are not yet known to the vendor or the public, meaning there are no patches or defenses available at the time of the exploit. This makes zero-day exploits particularly dangerous, as they can be used to compromise systems and data before any protective measures can be implemented.

In the context of cybersecurity, zero-day exploits are highly sought after by attackers due to their effectiveness. They present significant risks because organizations may be unaware that they are vulnerable, and thus they are unprepared to defend against such attacks when they occur. The name "zero-day" comes from the fact that the software developers have had zero days to fix the vulnerability before it is exploited.

While malware is a broader category encompassing all malicious software, and phishing and botnets involve different methods of attack or types of threats, it is the zero-day exploit that specifically relates to the exploitation of undocumented vulnerabilities, highlighting the unique nature of such attacks.