Likely the "encoder" or the person/group who processed the file.
This text follows a common naming convention for split archive files, typically used for high-definition video content. Breakdown: H4ll0w1nF1n4l: "Leet speak" for Halloween Final . 4K: Indicates the video resolution (3840 × 2160 pixels).
Specifies that this is the first segment of a multi-part compressed archive. .rar: The file extension for a WinRAR compressed folder.
To open this file properly, you would generally need all subsequent parts (part02, part03, etc.) in the same folder before extracting the first one.