Which signature is characteristic of a 7z archive header?

• A. 37 7A BC AF 27 1C
• B. 50 4B 03 04
• C. FF D8
• D. 89 50 4E 47

Answer: (A)

The main idea here is identifying a file type by its header signature (magic bytes). For a 7z archive, the header begins with the exact six-byte sequence 37 7A BC AF 27 1C. That unique signature is used at the very start of every 7z file, so tools can quickly recognize it as a 7z archive.

In contrast, the other sequences correspond to different formats: 50 4B 03 04 is the ZIP local file header signature, FF D8 is the JPEG start of image marker, and 89 50 4E 47 is the PNG file signature. Those are not 7z headers, so they wouldn’t identify a 7z archive.