A 3.25 MB ZIP archive labelled AM1M-A, a motherboard model for the AM1 platform judging by its name. The file name does not say what is inside, so it could be a BIOS dump, schematic or service documentation. Open it with 7-Zip, WinRAR or similar and inspect the files. Technicians use such material to revive a board with corrupted firmware via an SPI programmer. Always back up the original chip, confirm the image matches the flash size, and compare the model marked on the PCB.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @laptopchiplevelrepair. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.