I am trying to install Frama-c on a computer which can not connect to the internet because of the security but I can copy needed files to this computer using USB. The current operating system of this computer is Windows. However, I had some problems when trying to install Frama-c on Windows and in the homepage of Frama-c, they say that currently Windows isn't officially supported by Frama-c team. So I think it is better to install Frama-c on Ubuntu. Then I used Oracle VM Virtual box to install Ubuntu. Note that when I was installing Ubuntu I didn't have the internet connection, so I didn't install third-party software. Now I want to ask is it possible to install Frama-c in this case? If yes, what are files needed and where can I get them?
If you have opam installed on a machine with an internet connection, it should be possible to use opam-bundle, which is meant to create a .tar.gz archive containing all the ocaml dependencies necessary to install a given package.
Note however that system dependencies (in the case of Frama-C gmp and gtk C libraries) are apparently not included, so that unless they are included in the iso you have used to install Ubuntu, you will need to retrieve them separately.
Finally, note that opam is available on windows, at https://fdopen.github.io/opam-repository-mingw/installation/ and should let you install Frama-C on windows.