: .7z is a legitimate compressed archive format used by the 7-Zip software .
: It is widely believed to be an imitation of the "Smile Dog" or "Mariana's Web" style of creepypasta, designed to create a sense of digital dread. petitmary.7z
While the story is a popular piece of internet folklore, here is the reality of the file: low-bitrate audio file.
: Upon extraction, the archive is said to contain a series of highly distorted images of a young girl ("Mary") and a single, low-bitrate audio file. petitmary.7z