Enlarge / VPNfilter had a total of nine modular tools discovered thus far by researchers, potentially turning thousands of routers into a versatile attack platform. Previously unknown “ zero-day ” software vulnerabilities are mysterious and intriguing as a concept. But they're even more noteworthy when hackers are spotted actively exploiting the novel …

Enlarge (credit: Drew Angerer | Getty Images ) Just because a vulnerability is old doesn't mean it's not useful. Whether it's Adobe Flash hacking or the EternalBlue exploit for Windows, some methods are just too good for attackers to abandon, even if they're years past their prime. But a critical 12-year-old …