Internet-Security.com UDP port 5018 details

UDP port 5018 is registered by IANA as zenginkyo-3 for the Japanese Bankers Association’s Zengin Data Telecommunication System (“Zengin” interbank funds transfer protocol).
In practice, it is used on banking network gateways and host systems that connect to Japan’s Zengin interbank payment/clearing network (e.g., bank Zengin gateways and middleware used by major Japanese banks).
Outside this niche financial ecosystem, UDP/5018 has little to no use in mainstream software.

UDP 5018