My fav Indo horror story (nah it's a real story) is about a class of students in college. They get a text from their professor telling them to go to class. It was already night, but to not upset him, they came.
Oddly, the professor who was usually friendly, kind, and spoke easily was quiet. He didn't move and merely stood there.
This is when the class president got uneasy. Until she got a text from her actual professor, saying that there was no class tonight.
This freaked her out, so she dropped a pen to pick it up. Only to find out that the professor's feet wasn't touching the ground.
She urged everyone to get out of the class one by one, and since they all were scared, they did so.
The class president was the last to come out. Before she left, the professor put his hand on her shoulder and said,
"Sudah malam atau sudah tahu?" Which means, "is it because it's late, or do you know now?"
The fact this story is real always creeps me out.. What's a horror story from your country that is real?