This type of scanning looking for vulnerable BIND server is nothing new and has been ongoing for pretty much the past 20 years. Checking what might be exploitable, the last BIND advisory was released less than a month ago  and is remotely exploitable. This is an example of observable BIND Version scanning that could seen in DNS logs.
If you have DNS servers within your environment, have a look at the document provided by NCSC available here.
Jul 13th 2019
7 months ago