The Forge of God

The Forge of God (1987) is a science fiction novel by Greg Bear which gives a convincing account of an alien attack on the Earth which is accomplished by misdirection and the use of self-replicating von Neumann machines. It features a character (Lawrence Van Cott) clearly modelled on Larry Niven.

Warning: Wikipedia contains spoilers!

It is notable for the depiction of an American President whose effectiveness is compromised by his fundamentalist religious beliefs which are manipulated by the aliens.

Other memorable scenes and events include the discovery of an alien in the desert which clearly says in English "I'm sorry, but there is bad news", and its subsequent interrogation and autopsy; discovery of an artificial geological formation and its subsequent nuclear destruction by a desperate military; spider-like self-replicating machines; and the Earth's eventual destruction.

There is another alien faction at work, however, frantically collecting all human data, biological records, tissue samples, seeds and DNA that they can, and evacuating a handful of people from Earth; some of whom eventually settle a newly terraformed Mars, others to form the crew of a Ship of the Law to hunt down the origin world of the killers, a quest described in the sequel, Anvil of Stars

The two books show at least one solution to the Fermi paradox, with electromagnetically noisy civilisations being snuffed out by the arrival of self-replicating machines designed to destroy any potential threat to their (possibly long-dead) creators. (A similar theme is explored in Fred Saberhagen[?]'s Berserker novels).