图片隐写（持续更新）

admin • 2023-04-17 20:24 • 安全

文章目录

图片隐写基础1

题目地址 : https://ce.pwnthebox.com/challenges?type=1&diff=easy&id=92
010editor发现flag.docx，用binwalk分解

图片隐写基础2

题目地址 : https://ce.pwnthebox.com/challenges?type=1&page=1&diff=easy&id=93
binwalk分解无果猜测是lsb但是也没有可疑之处，尝试修改图片高宽

import binascii
import struct
import sys

file = input("图片地址：")
fr = open(file,'rb').read()
data = bytearray(fr[0x0c:0x1d])
crc32key = eval('0x'+str(binascii.b2a_hex(fr[0x1d:0x21]))[2:-1])
#原来的代码: crc32key = eval(str(fr[29:33]).replace('\x','').replace("b'",'0x').replace("'",''))
n = 4095
for w in range(n):
    width = bytearray(struct.pack('>i', w))
    for h in range(n):
        height = bytearray(struct.pack('>i', h))
        for x in range(4):
            data[x+4] = width[x]
            data[x+8] = height[x]
        crc32result = binascii.crc32(data) & 0xffffffff
        if crc32result == crc32key:
            print(width,height)
            newpic = bytearray(fr)
            for x in range(4):
                newpic[x+16] = width[x]
                newpic[x+20] = height[x]
            fw = open(file+'.png','wb')
            fw.write(newpic)
            fw.close
            sys.exit()

struct

与上题同理，爆破crc高度

第四扩展FS

题目地址 : https://ce.pwnthebox.com/challenges?type=1&page=1&diff=medium&id=444

词频分析脚本

from collections import Counter


f=open('file.txt','r')
f_read=f.read()


print Counter(f_read)
a=sorted(Counter(f_read).items(),key=lambda d:d[1],reverse=1)
print ''.join([i[0] for i in a])

LSB3

题目地址 : https://ce.pwnthebox.com/challenges?type=1&page=3&diff=medium&id=182

lsb隐写

X-man-Keyword

题目地址 : https://ce.pwnthebox.com/challenges?type=1&page=5&diff=easy&id=549

keyword: lovekfc

lsb检测到是用隐写数据的是有密码加密的所以zsteg才看不到

lsb extract X-man-Keyword.png 1.txt lovekfc


import string

enc = 'PVSF{vVckHejqBOVX9C1c13GFfkHJrjIQeMwf}'
grid = 'LOVEKFC' + 'ABDGHIJMNPQRSTUWXY'
flag = ''
for i in enc:
    if i in string.ascii_lowercase:
        index = grid.lower().index(i)
        flag += string.ascii_lowercase[index]
        continue
    if i in string.ascii_uppercase:
        index = grid.upper().index(i)
        flag += string.ascii_uppercase[index]
        continue
    flag += i
print(flag)

append

题目地址： https://ce.pwnthebox.com/challenges?type=1&page=3&diff=medium&id=132

binwalk分解出一些数据，把其中的二进制数据转换成图片

exp

1 import PIL
  2 from PIL import Image
  3 
  4 
  5 max = 32
  6 img = Image.new('RGB',(max,max))
  7 str = '0000000000000000000000000000000001111111000010101001000111111100010000010001000010100101000001000101110101010000011010010111010    00101110101101000001011010111010001011101000000100101110101110100010000010011011110010101000001000111111101010101010101011111110000000    00001010111011001000000000000000101111110010101101100110000001011000010010001000011010001000000010101101111011000111010100000011010001    11110011101011101000001001011100110101100101111011000000010101111010110101100101000000011110110010000000111111011110000110000010101101    00111100010100001110001110011101001100010111000010011001011111100010100000100000111000110001011100011001110010000101110110011111100111    00001010001110011100010011011011111001100000000000100101011011100011100000111111101110001000001010101110001000001001011011010010001110    00001011101011110001001011111101100010111010011000110111101001110000101110100100100000011010101000001000001001110110110011100101100011    111110010000100001110100100000000000000000000000000000000000000000000000000000000000000000000'
  8 i = 0
  9 for y in range(0,max):
 10     for x in range(0,max):
 11         if(str[i] == '1'):
 12             img.putpixel([x,y],(0,0,0))
 13         else:
 14             img.putpixel([x,y],(255,255,255))
 15         i += 1
 16 
 17 img.show()