Virus replicating through signals to civilizations

This is actually a pretty common trope in sci-fi.

There's a couple of the more obvious books that immediately spring to mind;

1) A for Andromeda by Fred Hoyle.

A new radio telescope picks up from the constellation of Andromeda a complex series of signals which prove to be a programme for a giant computer. After the computer is built it begins to relay information from Andromeda. Scientists find themselves possessing knowledge previously unknown to mankind, knowledge that could threaten the security of human life itself.

2) His Master's Voice by Stanislaw Lem;

Twenty-five hundred scientists have been herded into an isolated site in the Nevada desert. A neutrino message of extraterrestrial origin has been received and the scientists, under the surveillance of the Pentagon, labor on His Master's Voice, the secret program set up to decipher the transmission. Among them is Peter Hogarth. When he discovers that the TX Effect could lead to the construction of a fission bomb, Hogarth decides such knowledge must not be allowed to fall into the hands of the military.

Existence by David Brin matches what you're looking for. Civilizations build themselves into ruin after finding artifacts from space, and transmit more of the same artifacts that then infect other civilizations.