.EXE file signature
A PE Windows executable file begins with the bytes 4D 5A (MZ in ASCII) at the start of the file. The signature is the same whatever the file is named, which is why a renamed or extensionless PEBIN file is still recognisable.
Signature
| Offset | Hex | ASCII |
|---|---|---|
| 0 | 4D 5ADOS header. The 4-byte value at offset 0x3C points to the PE\0\0 signature (50 45 00 00). | MZ |
MIME type: application/x-msdownload · usual extensions: .exe, .dll
How to check a file's signature
Without installing anything: drop the file on our detector. It reads the bytes in your browser and shows the hex dump alongside the verdict; nothing is uploaded.
macOS and Linux (Terminal):
xxd -l 32 file.exe
file file.exeWindows (PowerShell):
Format-Hex -Path file.exe -Count 32If the bytes do not match
A file named .exe whose first bytes are something else is not a PEBIN file. The common explanations are a wrong or deliberately misleading extension, a download that saved an HTML error page instead of the file, or a container such as ZIP wrapping the real content. The detector reports what the bytes say; the PEBIN guide explains what a genuine file should contain.