This indicates an attack attempt against a Security Bypass Vulnerability in Shenzhen TVT DVR and OEM.
The vulnerability is due to hard coded default credential inside the vulnerable application. A remote attacker can exploit this to authenticate with the application to gain administrator level privileges on the target system.
Shenzhen TVT DVR and OEM with firmware released before February 2018.
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.