下载下是一个没有后缀的文件，使用winhex打开，头文件为50 4b 03 为zip文件，修改后缀，打开压缩包，是一大堆数独图片。
仔细看了好久，发现这几张图片像二维码，而且1 5 21这三张图的位置错了，修改之后，发现就是个二维码，用记事本将信息记录下来，有数字的用1代替，没有的用零代替。
111111101010101000101000001111110000101111111
100000101100111101010011101100011001001000001
101110101110011111010011111101000101001011101
101110101101100010001010000011110001101011101
101110100011100100001111101111111011101011101
100000101100100000011000100001110100001000001
111111101010101010101010101010101011101111111
000000000011001101001000110100110011100000000
110011100100100001111111100100101000000101111
101001001011111111101110101011110101101001100
100000111100100100000110001101001101010001010
001100010011010001010011000100000010110010000
010110101010001111110100011101001110101101111
100011000100011100111011101101100101101110001
001100110100000000010010000111100101101011010
101000001011010111110011011111101001110100011
110111110111011001101100010100001110000100000
110101000010101000011101101101110101101001100
010011111110001011111010001000011011101101100
011001011001010101100011110101001100001010010
010111111111101011111111101101101111111111100
011110001100000100001000101000100100100011110
111110101110011100111010110100110100101010010
110010001011101011101000111100000011100010000
101011111011100111101111111100001010111110010
110100011000111000100111101101111101000100010
111101111110001001000011010110001111110111110
011001010101000110010100010001000101101010001
011101110101101101100100001101101000111101001
110110001001101100010101101111110100101100110
000011100111000000000100001010101111100010010
111010010011110011101110010100001011111010010
101001100010111111110100000100001010101010100
000010011001001101110101001111100101111101101
000010111101110001101011000001000101110100110
011110011010100010100000011011000001110010000
100110100100001101111111101100101110111110011
000000001111110101101000101011100100100011010
111111100011111011011010101101110011101011110
100000101110101101101000111110010001100010001
101110101011100001111111101101001000111111011
101110100110111101101000001001101100011101101
101110100000011101100001101010110010010010001
100000101011001011111011001011000011010110000
111111101010101001111011110101101110000101101
然后使用python写个脚本来生成图片。
from PIL import Image
x = 45
y = 45
im = Image.new('RGB', (x, y))
white = (255, 255, 255)
black = (0, 0, 0)
with open('D:\py\新建文件夹\ss.txt') as f:
for i in range(x):
ff = f.readline()
for j in range(y):
if ff[j] == '1':
im.putpixel((i, j), black)
else:
im.putpixel((i, j), white)
im.show()
使用qr research扫描得到base64的编码。
多次解码得到flag。