CUR is a Microsoft Windows cursor format.
CUR files can have multiple icon images of different sizes in the same file, so that programs displaying them can pick the size that is appropriate for a particular use. Image data within the file is either in BMP or PNG format, with some header bytes defined by the CUR standard.
Files have a 6-byte fixed header, followed by one or more 16-byte directory entries, followed by the image data.
CUR format is very similar to ICO (icon) format.
Files begin with bytes
00 00 02 00.
- ICO (Wikipedia) (also describes CUR)
- GFF Format Summary: Microsoft Windows Cursor and Icon