Back in September 2012, CloudFlare reported that cybercriminals were relying on misconfigured DNS resolvers, also known as “open DNS resolvers,” to amplify their distributed denial-of-service (DDOS) attacks.
At the time, the company listed the names of several companies that hosted a large number of open resolvers. Now, CloudFlare proudly announces that their number has dropped by 30% across the Internet.
After CloudFlare had published the report in which it highlighted how cybercriminals could take benefit from these misconfigured resolvers, the affected organizations started taking measures.
While a 30% drop is significant, there are still numerous open resolvers out there, so CloudFlare encourages network providers to contact it if they want help in cleaning up their infrastructures.
It’s important to note that cybercriminals can amplify their DDOS attacks 50 times by abusing open resolvers.