The following was received via email: (from the Lower Mainland, British Columbia) The slender flower spikes which can reach about fifteen inches, sport flowers that have pinkish and white cups that are lined with a deep chocolaty, waxy finish. The overhanging hood sports a bright yellow knob on the newest flower which fades. The flowers are in turn encased in a small thimble of green leaves which resemble pixie caps! I have always had these slender orchids in a few spots, but this year they have popped up every where in the garden. Much obliged.
Based on the description of the flower, and the plant's behaviour in your garden (spreading), I'm fairly certain that this is Epipactis helleborine, commonly known as helleborine. Here are a few links, with pictures: Connecticut Botanical Society Orchid Society at the Royal Botanical Gardens (Hamilton) Orchids of Wisconsin It is worth noting that on the last web site, they describe the plant as being aggressive and invasive, or as you described, "popping up everywhere". Whether or not you need to be concerned about its invasiveness depends on your situation. If your yard backs onto a public park or woodland, I suggest monitoring the local area to ensure that it is not spreading into the native flora. If it is only spreading in your garden, then simply pull it out before it sets seed.