An HR employee began having issues with a device becoming unresponsive after attempting to open an email attachment. When informed, the security analyst became suspicious of the situation, even though there was not any unusual behavior on the IDS or any alerts from the antivirus software. Which of the following BEST describes the type of threat in this situation?

A.
Packet of death

B.
Zero-day malware

C.
PII exfiltration

D.
Known virus

Explanation: