Selamun Aleykum,
I study Computer science and need to do an Internship. I will not deal with haram activities like riba. I will only deal with security, development, data etc. Would it be still haram to work there since their main income is haram?
Wasalam
May Allah bless you.
If there are no other halal alternatives available to you, then yes, in my personal opinion you may do the internship at a conventional bank.
And Allah knows best!