got malware/virus from installation

I am doing this as a courtesy, so I don't have time to give more details that you will find here. I tried to just notify adobe but they seem allergic to their own customers. I had to acquire a very old imac because I own the disc version of the CS suite that I paid $1400 for and I do not feel like paying a monthly fee now. I have been upgrading everything to the furthest point I can that still allows the suite to function. I ran into trouble when a website complained about the flash player. I couldn't install the most recent version as it won't work on this osx version. (details below) So, I searched adobe's site for previous versions and found a section where developers could obtain such things. I have double checked the link and it is a valid adobe link.

When I installed the old version of flash player it brought a friend along. It commandeered my browser and did the usual song and dance about the machine being infected and how i must do blah blah blah. Nah. I quit the browser and got back in but I simply will not log into anything until I can get this dealt with. I am currently using my pc laptop to log in here. This is no small deal... that imac is critical to the design aspect of my business. I cannot easily do a virus scan bc the osx version isn't supported anymore and I am having a hard time locating the upgrade to the next couple of OSX versions. So I can't just easily get rid of this and I am just really unimpressed that adobe isn't doing a better job of keeping these downloads clean.

Please do not tell me it couldn't have come from adobe because adobe is the only place it could have come from.

I am running osx 10.8.5 (until I can obtain a copy of 10.9 and 10.10)

Using chrome browser

the website was https://helpx.adobe.com/flash-player/kb/archived-flash-player-versions.html

The file downloaded was: fp_13.0.0.250_archive.zip

I installed the mac version contained within that

Now I can't use my imac to log into anything until I am certain that whatever this malware or virus is has been cleaned and I can't just run a virus checker etc. So thank you adobe for your bang up job of having trustworthy downloads