QResource gives wrong data for embedded binary file

I am unable to get to the data of an embedded binary file. The binary file is 43116 bytes, but when opening it using QResource, size() reports a size of 818 bytes, and data() points to garbage (or perhaps compressed data?)

This happens with all Qt versions I tried: 5.6.3, 5.9.7 and 5.12.1. (Using the official Linux 64-bit binary installer.)

resources.qrc file:

<RCC>
 <qresource prefix="/">
 <file>data.bin</file>
 </qresource>
</RCC>

qmake project:

QT -= gui
CONFIG += c++11 console
CONFIG -= app_bundle
SOURCES += main.cpp
RESOURCES += resources.qrc

main.cpp:

#include <QCoreApplication>
#include <QResource>
#include <iostream>
int main(int argc, char* argv[])
{
    QCoreApplication a(argc, argv);
    QResource res(":/data.bin");
    std::cout << res.size() << '\n';
}

This prints "818" and res.data() points to garbage.

"data.bin" is attached.