What do you think this is?

As everybody probably knows by now, CCleaner was compromised and malicious individuals added multi-stage malware payload on it. A typical case of compromised software if you ask me, pretty much like the one with the Ukrainian tax software that spread Not-Petya. But there is a different aspect to why compromised software is very dangerous, and it actually uses (believe it or not) social engineering in a more advanced way.

It looks like we're in the middle of one of the worse attacks in the last decade. The WannaCry attack has already crippled more than 230.000 computers, in more than 100 countries.
We already saw big organizations like Telefonica and the NHS, like Renault and Deutsche Bahn having their operations impacted. And it's not over yet. But...