I'm going to cheat a bit and include non-functioning satellites, just to give a flavor of what this does. The Surveyor 3 lander was visited by the Apollo 12 crew approximately 2 years after it landed on the moon. There was a complete report done to analyze the status of the satellite after it's time on the moon, including micrometeor impacts.
The report states:
A major effort in the analysis of Surveyor 3 parts has been the search
for hypervelocity impact features-an effort roughly analogous to the
search for the needle in the haystack. A great number of low-velocity
features exist that were caused by lunar particles striking the
surfaces due to Surveyor and Apollo landing events, handling of the
material, and natural phenomena. The 1- to 4.5-um size of the surface
features prohibited the effective use of optical instruments. However,
all participating investigators concluded that no material or surface
features were found that definitely could be stated to be meteoritic
Okay, so what does that mean? Basically, there were no "Primary" events discovered, where a micrometeorite hit the spacecraft directly from space. However, they also wanted to discover the secondary rate, where a dust particle from a far away impact hit the spacecraft. They looked at the optical fibers, and found:
Particles 1 pm and larger with velocities high enough to produce
plastic flow in glass were found to be about l0^3 times the cratering
rate expected for primary micrometeoroids. The rate is approximately
800 impacts per square centimeter per year for impacts greater than 1 um.
Bottom line is, there was some slight meteoric damage to the spacecraft, but not significant. The rate is relatively low, and most spacecraft can easily handle that kind of impact. This is definitely a danger which should be carefully watched out for during lunar activities, especially of the secondary type. There is more importance to put shielding on the sides than above the spacecraft.