It's not exactly incorrect to omit "the" but it reads like Journalese - that is, like a piece of journalism written with the conventions of a journalist rather than an ordinary person.
You can complicate your example further by dropping "giant software":
"It is from a report of company Microsoft"
Now this reads as very odd, not at all native-speaker English. Whereas this does not seems so odd:
"It is from a report of the company Microsoft"
I'll use these two instead to elaborate. Here we have two noun phrases, "the company" and "Microsoft." These types of constructs, where we have two adjacent nouns are called appositions and this specific variety is called a restrictive apposition. There are many companies that could be "the company" but the one we're referring to in particular is Microsoft. Compare to the second restrictive apposition from the wiki article I linked above, where "the television show The Simpsons" is used as an example. The same concept applies in your question.
In short, "the giant software company" is your noun phrase and "Microsoft" is acting as a further descriptor of "the giant software company." The definite article "the" is required because "company" is your noun, not "Microsoft."