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Madoka.exe
From Screamer Wiki
MADOKA.exe(Mostly known as "Ghost virus" or "Sadako virus" in Japan) is a japanese Joke program, it is a variant of the application Hikaru.exe. When you run the program, a picture of a japanese woman in full-screen is displayed, but it disappears and some chinese texts are displayed in the upper-left corner. However, a "ghost version" of the woman image will appear along with a scream sound effect, when it ends, it will immediately return to the woman picture. The screamer picture will appear suddenly.