=== B1: steghide trich tu JPG ===
FLAG{steghide_jpg_works}

=== B2: steghide trich tu WAV ===
FLAG{steghide_wav_works}

=== B3: append ZIP sau PNG - binwalk phat hien + unzip lay ra ===

DECIMAL       HEXADECIMAL     DESCRIPTION
--------------------------------------------------------------------------------
0             0x0             PNG image, 120 x 80, 1-bit grayscale, non-interlaced
270           0x10E           Zip archive data, at least v1.0 to extract, compressed size: 40, uncompressed size: 40, name: s.txt
448           0x1C0           End of Zip archive, footer length: 22

-- unzip phan dinh kem --
  (attempting to process anyway)
 extracting: out_append/s.txt        
-- noi dung file giau --
co mat khau trong day: FLAG{append_zip}

=== B4: exiftool doc metadata an ===
Artist                          : HaiND
Comment                         : hidden-note FLAG{exif_meta}

=== B5: LSB tren PNG - trich bang lsb.py ===
thong diep giau: FLAG{lsb_png_works}
-- so khac o muc PIXEL (mat thuong khong thay) --
so pixel bi doi: 81 / 40000 ; muc doi lon nhat moi kenh: 1 (chi LSB, tuc +/-1)
