According to the participants online, when the image was opened in a text editing program, a cryptic message appeared that was interpreted as a Web address. Those who were trying to solve the mystery were led to a website, which in turn led to a Reddit.com forum called “a2e7j6ic78h0j” that revealed a series of symbols and coded messages.

Several more clues were uncovered — including hidden messages that suggested the key to breaking the code was already posted on the a2e7j6ic78h0j forum. Once decoded, a U.S. phone number was revealed.

The number, which has since been disconnected, had a message for callers that was yet another clue. This time, a riddle led to a website that had a picture of a cicada and what appeared to be geographic coordinates.

According to online reports, posters were found at some of the locations around the world, including Paris, Warsaw, Seoul and Miami. Each poster had an image of a cicada and a QR code that, when scanned, revealed a message.