All tax money in Russia and elsewhere is stolen and therefore dirty and corrupt to begin with anyway. Try not paying taxes and you'll get jailed -- and if you refuse this you'll get gunned down. I think doing anything you can to avoid paying taxes without getting yourself into trouble is a moral obligation.
Ha. I've been thinking about these sorts of problems and I'm leaning towards the idea that while governments are legitimate (groups of people pooling resources to achieve communal goals with some degree of compromise) most citizens are not legitimate (for lack of a better word). I was born in the US so I get all these rights, benefits, and obligations with no choice. From that viewpoint are immigrants the only "true"…
The criteria for citizenship have varied a lot over time, and usually have to do with the economic or identity system of the country.
For example , when the US was an agrarian society, African slaves could not be citizens, because doing so would undermine the economic system underpinned by slavery.
Today, some middle eastern countries have religious requirements for immigrants to become citizens.
The modern concept of a citizen (vs a subject) is itself only a few hundred years old.
So I'm not sure if there is a "true" definition of a citizen, in any morally defensible way.