If you own Hikvision security cameras you would have noticed the sudden change in the live feed display where the normal footages were replaced with the term HACKED. However, it isn’t the case with all Hikvision security cameras but only some of them but if you are the owner of one such camera then it is obvious that there is a backdoor in the device.
Read more here: https://www.hackread.com/hikvision-security-cams-compromised-to-display-hacked/