Ethics of using company data from internship for academic project
You should ask the company where you do your internship. Perhaps they are fine with whatever you want to do. Perhaps they will allow you to use their data but only release summaries, not the raw data. Perhaps they will require you to anonymize it.

In addition, how will you do the analysis? Will you take the company's data and transfer it to your own computer? (This may well not be welcomed by the company.) Or do you plan on using a company-supplied machine to do your analyses? (Same problem - companies don't necessarily like it if you use their hardware for what are essentially personal tasks.) Do you want to install third party software to analyze your data on their machines?

Think through what you want to do, then go to your supervisor. Depending on their personality, people may even be interested in working with you on this, perhaps get a publication out of it.

Whatever you do, don't, don't, don't just use the data without asking. Whether or not you sign an NDA.