Try to contact a person that is directly involved in the research you would like to work on and ask them about internships. If you have to go through HR or some front portal like that (because you do not know people working in your group of choice), use specific keywords in your request so they can forward the request to the right person. Don't ask if they need it, just attach your cv and anything they might need to the mail.
I do not have internships advertised somewhere, but if a student mails me (because the university forwards students to me or my direct colleagues), and his/her cv looks good and the student wants to work on a topic that I'm interested in, I am always willing to create an internship position. At the moment I have 3 MSc. students working from home. Not ideal, but 2 are pure computer simulation projects and the other student was already (mostly) finished with her lab work.
I'm not in the US, so it will probably be difficult to offer you an internship, sorry :-)