What's agressively polluting Google results?

What is going on with Google search results? It seems no matter what I search for, somewhere down the first page I start to see results crowding out real results with either:

- A random 4-letter 3rd level domain (xxxx.domain.foo), or

- A random 4-7 character first level URL path (foo.wtf.co.za/xxxxxx/stuff)

and either no content or wordvomit, usually with an embedded search box. These look like some kind of DNS hijack, and is clearly intended to game the Google system, but I can't really see what the end-game is. Some searches I've been doing after the first result page are more than 50% one of two of these dead-end searches.

Interestingly, I get 404s if I try and wget these. I've been otherwise using Firefox.

WTactualF is going on?

For example:

http://junglegymsfrik.co.za/zpg2yth/motorola-68000-block-diagram.html

http://zlxp.fewo-bokel.de/68000-processor.html

http://lkkv.helloplugin.de/how-to-calculate-delay-in-assembly-language.html

http://mmgs.newhazel.de/microprocessor-manufacturing-process.html

http://krypsoninfomatics.com/kpbz/intel-serial-io-reddit.html

http://vhos.primadonnamd.de/8086-programs-github.html

http://vujz.jwplz.de/pc-power-supply-problems-and-solutions.html

http://yayu.codrin.it/8086-microprocessor-simple-projects.html

http://adaj68.fr/nytk6/mips-reverse-string.html

https://lumbreco.com/gjdz/motorola-68040.html

http://upei.supp-corner.de/z80-vs-8086.html

http://qysy.charitygolfer.de/amd-cpu-compatibility.html

http://sxwj.spielort-theater.de/ubuntu-nomodeset-amd.html