The rest of the sentence quoted above is "... working out of the agency’s headquarters on Grizodubovoy Street in Moscow."
Which could also mean an intelligence officer('s personal machine, who is known to be) working out of the agency's hq...
It implies that the IP was from GRU HQ, but the only definite statement is that it is this specific officer, who works at this specific location.
But would they actually work from a known location id assume that US offensive operations are not done directly from Langley
It wouldn’t be too hard for the Russian govt to set up shop in a residential neighborhood.
Or, at least, have a network exit point at an unsuspecting family home.
Yes I suppose that could be the other explanation
@walshemj: "But would they actually work from a known location id assume that US offensive operations are not done directly from Langley"
You forget this story is aimed at people who mostly get their news from Faux Television ..