It looks like a 32-bit Qt 5 version built with MingW and GCC 4.91 delivered in an incomplete zip file. The project seems quite dormant: https://sourceforge.net/projects/drm
You should be able to substitute all the Qt libraries and plugins from a recent 32-bit Qt 5 version built with MingW. Fairly sure that the Qt Online Installer offers that combination (no Windows box to check)