An example of this can be found in the Ponderosa Pine tree (Pinus ponderosa), which produces a terpene called myrcene when it is damaged by the Western pine beetle. Instead of deterring the insect, it acts synergistically with aggregation pheromones which in turn act to lure more beetles to the tree. 
Specialist predatory beetles find bark beetles (their prey) using the pheromones the bark beetles produce. In this case the chemical substance produced is both a pheromone (communication between bark beetles) and a kairomone (eavesdropping). This was discovered accidentally when the predatory beetles and other enemies were attracted to insect traps baited with bark beetle pheromones.
Pheromones of different kinds may be exploited as kairomones by receivers. The German wasp, Vespula germanica, is attracted to a pheromone produced by male Mediterranean fruit flies (Ceratitis capitata) when the males gather for a mating display, causing the death of some. In contrast, it is the alarm pheromone (used to communicate the presence of a threat) of an ant (Iridomyrmex purpureus) that a spider predator is attracted to.