After the macOS Catalina update to version 10.15.4, released on March 24, 2020, all Bitdefender users will probably see this warning:
Legacy System Extension
Existing software on your system loaded a system extension signed by “Bitdefender SRL”, which will be incompatible with a future version of macOS. Contact the developer for support.
Apple has already announced that the next major version of macOS will deprecate the support for kernel extensions. Specifically, Apple will replace kernel programming interfaces (KPIs) with EndpointSecurity and NetworkExtension APIs, which technically are entirely different. Technical details are available in this Apple article – Deprecated Kernel Extensions and System Extension Alternatives.
Here at Bitdefender, we are aware of this change. We are currently working on a new version of Bitdefender Antivirus for Mac and we will provide full support for this technology before the official release of the next macOS version, which is expected later this year.