Malware that changes its characteristics and thereby makes signature detection more difficult is described as _____.

### Why this is right The lesson calls malware that constantly changes its signatures or characteristics **polymorphic**. These changes can make it harder for detection based on fixed signatures to recognize it. ### The concept A signature is a recognizable pattern associated with known malware. If malicious software changes its observable pattern, a detector relying on one unchanged signature may fail to match it. This is one reason security should use multiple defenses and stay current, rather than depending on a single detection method. ### Terms - **Polymorphic malware**: Malware that changes characteristics or signatures in ways that can help it evade detection. - **Signature**: A recognizable pattern used to identify a known threat. ### Remember Changing malware can defeat defenses that rely on a fixed pattern.