Thanks Stephen Piriform, and others who offered suggestions!
The installer's properties seemed to me to be legitimate, but they could have been spoofed--I don't know.
The ccsetup554 setup program launches in a language other than English. I live in the US.
This is the first time I have installed CCleaner on this system, Win7 Pro, Ver 6.1,SP1, on a HP Probook 4540s.
Which site should I go to for a version that launches in English, please? Thanks.