Backlink from a irrelevant source

[anush]

If something links you back then its called backlink right? Say I have got a link from a source which I am unheard of and also unaware. Its from my niche but the source page and division of the site which is linking me is totally non-sense.

Should I be still penalized for this link?

Just a backlink won't penalize your website. if the link is from the adult domain or spammy domain than you have to worry.

As OP said its from the niche. So, I don't think its going to be a problem.