According to one news report, a new version of Mirai has recently been released causing an increase in the number of scans against port 2323 and port 23. According to our firewall logs, the number of scans against tcp/2323 has increased over the current month :-
There is indeed a big increase on the 22nd when the new malware was released, but interestingly enough, there is also a big increase in the week before, indicating that perhaps the new Mirai variant was released earlier than the researchers identified.
As a comparison, the same graph for tcp/22 – ssh, and a very heavily probed port looks like :-