I recently decided to clean install Windows 10 on my machine. On searching online, I found that windows with update 1703 was the latest. I have acquired the iso file for windows 10 enterprise from a friend of mine who says he downloaded it from a website and not from the official Microsoft site. The iso file says it is a 12 in 1 iso with an option to install any version of Windows (home/pro/education/enterprise) and that too with English or Russian languages. My question is
Is it possible that someone could have done something nasty to the actual iso file and came up with a corrupted version of the OS? Like, is it possible that after installing from the iso I will have my windows with pre installed malware? Like someone modifying some critical system file and writing their own corrupted code?
Is it possible someone could've modified some setup files and then added their own malicious code in between the lines? Like how they show using PE view hexplorer and other tools?
I might sound stupid, but I've been a victim of a ransomware attack lately and don't want to risk anything again.
My current bandwidth is too slow to download any official iso from the Microsoft site.
Yes, it is very much possible that the OS comes with preinstalled malware. It is perhaps even likely. You could scan it with AV, but even if it comes up clean there is still a significant risk the AV missed something. Perhaps you could compare the checksums of the file with the checksum of the official Windows file, but since I don't think Microsoft publish Windows in ISO format you might be out of luck there too.
Basic moral of the story: If you care about security, don't use pirated software.