"I'd like to suggest that while pundits are citing slow progress for patching Heartbleed, that in actuality, the Heartbleed issue is responsible for the sudden change," said Kevin Shortt, an incident handler at ISC, Monday in a blog post. "The month of May showed an extensive effort for patching and truing up patch levels because of Heartbleed. This effort likely assisted in the NTP issue being patched along with it."
However, the danger that insecure NTP servers pose to the Internet is not completely gone. According to NSFOCUS's data the number of vulnerable servers with an amplification factor of over 700 has actually increased since December, to 2,100.