https://isc.sans.edu/forums/diary/Wireshark+300+and+Npcap/24730/

Starting with version 3.0.0, the Wireshark for Windows installation programs are distributed with Npcap in stead of WinPcap. Prior Wireshark Windows versions already supported Npcap, but the installer still came bundled with WinPcap.  Npcap is a library for packet capturing and sending on Windows, developed by the Nmap project, and is actively maintained, while WinPcap is no longer actively maintained (unless WinPcap’s community steps in).  If you have a prior version of Wireshark installed on Windows (like 2.6.7), and you perform an upgrade to 3.0.0, Npcap will be installed by default: