On April 20, 1967, the unmanned lunar lander Surveyor 3 landed near Oceanus Procellarum on the surface of the moon. One of the things aboard was a television camera. Two-and-a-half years later, on November 20, 1969, Apollo 12 astronauts Pete Conrad and Alan L. Bean recovered the camera. When NASA scientists examined it back on Earth they were surprised to find specimens of Streptococcus mitis that were still alive. Because of the precautions the astronauts had taken, NASA determined that the germs were inside the camera when it was retrieved, so they must have been there before the Surveyor 3 was launched. Apparently, these bacteria had survived for 31 months in the vacuum of the moon's atmosphere.
A favorite story, but possibly due to sloppy handling.