Really, I'm surprised the attacker would pick ISO as an attack file. I didn't think users could easily open it by default. Not as easily as many other file types anyway...
What damage can a malicious .iso file cause without explicitly executing it?
A malicious file in this case would be a program of unwanted actions to take on your computer. If the program is not executed, then it is as safe as a printed product.
have a question about a downloaded "bad" file, i was redirected to a page from a link and, because i used chrome, it automatically downloaded a .iso file and saved it on the C drive in the downloads folder.
Google Chrome has a built-in list of file types that have the potential to be used in drive-by attacks, in other-words file types that can be executed automatically.
Viruses do not execute themselves, but certain file types (i.e.
.dll) can be placed such that they are executed by another program automatically. ISO is not among those types.
I am confident that the file is malicious and I immediately removed it and also removed it from the bin, on windows. Is it possible for the .iso file to do something bad without me clicking on it or mounting it?
No, just keep in mind some hackers use Click-Jacking to get you to automatically open the file once it appears in the download tray. Fortunately, for ISO this is less of an issue, and there is a built-in delay in Chrome to help prevent Click-Jacking.
or am i safe because I deleted it quickly?
Well time doesn't really relate, but for the reasons above, it looks like it could not have done damage.
Thanks for the help! - and if it is bad, any suggestions on fixes? I simple just re install windows.
If your computer were hacked, the first thing would be to immediately cut internet access to prevent theft of your private files, or installation of additional badware. A full OS re-install is the safest option, as anti-virus does have its limits. There are rare cases where viruses can install themselves into the flashable firmware of various hardware on your computer, but that is uncommon due to the higher development cost on the part of the attacker.
Sounds like the attack was unsuccessful. :-)