The kern log file

Hello. The kern.log file is full of these logs of attempted attacks. When I disable in CSF they stop appearing. Is this normal or should I be worried?

Webmin version 2.111 Usermin version 2.010
Virtualmin version 7.10.0

May 25 10:22:09 cp kernel: [44210.702800] Firewall: TCP_IN Blocked IN=eth0 OUT= MAC=00:50:56:4e:2e:e6:74:83:ef:4e:ad:b9:08:00 SRC= DST=84.247.**** LEN=44 TOS=0x00 PREC=0x00 TTL=249 ID=54321 PROTO=TCP SPT=52343 DPT=1800 WINDOW=65535 RES=0x00 SYN URGP=0

I wouldn’t worry about it.