My unqualified hunch: if they did that, then a mitigation against such malware could be for the OS to serve completely deterministic data from /dev/random for all but a select few processes which are a priori defined.
If it were me, I'd combine urandom (or equivalent), high-res timestamps, and clock jitter (sample the LSB of a fast clock at "fixed" intervals where the interval is a few orders of magnitude slower than the clock resolution), and hash them all together.