From the perspective of NSO developers, they are helping prevent the next attack against civilians somewhere. I can’t fault them for that.
in some societies it’s “immoral” not to rape someone as punishment or to not kill a “unclean” ethnicity and your definition supports that
Most societies make an exception for killing enemies of the state. Soldiers are seen as heroes fighting for their country not as immoral killers.
They are selling spy software to regimes that are known to kill civilians. Ergo they are not preventing attacks against civilians; they are enabling attacks against civilians. No moral relativism necessary.
Even with respect to Israel’s “counter” terrorism efforts, if the NSO development team’s motivation is to prevent attacks on civilians, then enabling Israel to attack and kill civilians is something for which they are morally culpable.