"Newspaper" and "New York Times" are concrete nouns, not abstract.
You can see that by the way they are used:
The newspaper is on the table
The New York Times was wrong about Trump's chances of winning.
Abstract nouns do not designate any thing that can be over a table, or that can be wrong about elections:
?Justice is on the table (only possible if the table here is metaphoric).
?Freedom was wrong about Trump's chances of winning (only possible if "freedom" here is the name of something else, such as magazine or a person).
(ETA, see Conifold's comment below)
Philosophically, there is something like "abstraction", which is a complex issue.
Also philosophically, there is some thing like "indivisibility of matter". When Greek philosophers first thought about this issue, they concluded that matter could not be infinitely divisible - so there should be a minimum amount of matter that could not be subdivided. They then called this minimum "atom", which meant, in their language, exactly "indivisible".
As alchemy transmutated (pun intended) into modern physics and modern chemistry, that concept of "atom" was reapropriated; the modern concept of "atom" no longer implies indivisibility (though its division is by no means inconsequential): we know an atom is made up of protons, neutrons, and electrons (and a few other less famous particles), so we can divide it conceptually - and we can also divide it physically - which is what a fissile atomic bomb, or a nuclear reactor, are about. Philosophically, we can still discuss whether matter can be infinitely subdivided (we now have, perhaps provisorily, agreed to the idea that subatomic particles can be further subdivided into "quarks", but that quarks themselves are indivisible). Until another paradigm change comes, quarks are what correspond to the philosophical concept of "atom"; conversely, atoms are quite complex particles, made of several different internal structures; they are still the minimum amount of matter that preserves the chemical properties of an "element".
Similarly, the linguistic concept of "abstract" noun has been detached from the philophical concept of abstraction. All names - all words indeed - are "abstractions" in one level or other, even proper names, as the continuity between today's John and yesterday's John is abstracted from the different beings each are. But an "abstract noun", in linguistics, is a "noun" that behaves syntactically (and semantically, and pragmatically) in certain ways, different from "concrete nouns". If a noun behaves in such ways, it is abstract; if not, it is not abstract, and we call non-abstract nouns "concrete nouns", regardless of the fact that they are abstractions already.
For instance, an abstract noun does not make phrases with precedents such as "taste of...", "colour of", "smell of", etc. (not without changing radically the meaning of the words "taste", "colour", "smell"). We say "taste of chocolate", but not "taste of freedom", because "freedom" is an abstract noun; and if we eventually say "taste of freedom", we understand that we are not talking of "taste" in the same sense as in "taste of chocolate"(1) (or, of course, that we are not talking of "freedom" in the same sense as in "freedom for the people" - perhaps Freedom[tm] is just another brand of chocolate, which is what we probably understand from a construction like "Freedom tastes not like chocolate, but like chocolate up to eleven").
As such, the "abstractness" of a noun is part of the internal context of a given speech, and helps us understand what we are talking about. But we shouldn't take philosophical conclusions from the fact that a noun is abstract, more than what is common knowledge about things we speak of. "Ghost", "goddess Athena", or "phlebotinum" are no more material than "justice" or "beauty", but they are concrete nouns or expressions.
(1) This is what we call usually "figurative sense", which apparently some philosophers think is a misnomer, and, worse, entangled with Platonic reifications of language. But whether "figurative" or not, I suppose it is easy to see it is a different sense; the "tastes" of chocolate, carrot, or peppermint are very different, but are still something we perceive with our tongues; the "tastes" of freedom, political correctness, or madness are not merely different, but are perceived in a very different way, perhaps with our brains, or our whole bodies.