1. The malware was released last October but remained undetected by antivirus tools until this month.

2. Security researchers are considering buying undetected software security vulnerabilities from a notorious group of hackers.

3. The fact that a breach of this magnitude went undetected at a tech giant like Yahoo for two years is astounding.

4. That investigation, which was publicly released, found that a fire in a launcher equipment room went undetected for five days.