Are carbon fiber/composite aircraft at greater risk from lightning? Modern jetliners are protected from lightning by their metal skin. When they are struck by lightning, the electricity almost invariably travels through the skin and out the other side without damaging the internals or passengers. 

While carbon fiber is electrically conductive, I have not been able to find any resources with a direct comparison between it and aluminum. This forum post would seem to suggest that it is less conductive, mentioning that 


  Although partially conductive, carbon fiber materials, and carbon fiber masts, are regarded as non-conductive (nonmetallic) for the purpose of this technical information report. For lightning protection, carbon fiber masts require the addition of an air terminal and primary conductor as described elsewhere in this technical information report. 


Is carbon fiber as electrically conductive as aluminum, and if not, does this pose a problem in the event of a lightning strike?
From Boeing's AERO:


  Areas that have the greatest likelihood of a direct lightning attachment incorporate some type of lightning protection. Boeing performs testing that ensures the adequacy of lightning protection. Composite parts that are in lightning-strike prone areas must have appropriate lightning protection.
  
  Lightning protection on airplanes may include:
  
  
  Wire bundle shields.
  Ground straps.
  Composite structure expanded foils, wire mesh, aluminum flame spray coating, embedded metallic wire, metallic picture frames, diverter strips, metallic foil liners, coated glass fabric, and bonded aluminum foil.
  


That suggests for composite areas that are vulnerable to lightning strikes, extra measures are taken to enhance the conductivity.