If you're running a Mikrotilk router to connect to the internet, please check your firmware is up to date.
Today I've noticed four UK-based hosts repeatedly trying to connect to my firewalls on TCP 23 (telnet) and TCP 7547.
I did a bit of poking around and determined that three out of four are definitely Mikrotik devices. The fourth may be too, I'm not sure.
There's a vulnerability currently being exploited on Mikrotik routers and it's been discussed on the Mikrotik forums at https://forum.mikrotik.com/viewtopic.php?f=2&t=13236...