xctf offensive and defensive world MISC master advanced area Erik-Baleog-and-Olaf (two ways of thinking)

First of all, thanks to the xctf attack and defense world platform for providing the topic

Secondly, thank you readers for your support ( •̀ ω •́ )y, if you have any questions or suggestions, you can chat with me privately

Table of contents

The method is to directly spell the QR code

Method 2 with script

Summarize

Come on everyone ( •̀ ω •́ )y look forward to seeing you again

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Erik-Baleog-and-Olaf

The method is to directly spell the QR code

The download attachment is a file without a suffix

010 come on wave

 It was found that it was in png format with a suffix

 There is a website for this second method that says

 PNG format plus suffix

Get the following picture

 Open with the stegsolve tool

Found a QR code in the middle

 

But I can't scan it and pick a few clearer pictures

 Use ps to piece together a complete QR code

Finally, you can get the flag by scanning with QR Research software. Scanning with WeChat is not as sensitive and fast as QR Research

get

flag{#justdiffit} ( •̀ ω •́ )y

Method 2 with script

As mentioned above, there is a website

After opening, you can download a picture

22kurzm.png Image downloaded from the last line of website in 010
stego100.png The picture given in the title 
result.png The final QR code

from PIL import Image
exp = Image.open("22kurzm.png") # 从010中最后一行网站下载的图片
cipher = Image.open("stego100.png") # 题目给的图片
new = Image.new("RGBA", size=exp.size)
for i in range(640):
    for j in range(480):
        y_p = exp.getpixel((i, j))
        c_p = cipher.getpixel((i, j))
        if y_p == c_p:
            pass
        else:
            new.putpixel((i,j), (255,255,255))
new.save("result.png")

 Run the script to get the QR code directly

Scan code to get

flag{#justdiffit} ( •̀ ω •́ )y

Summarize

This question is not difficult, the main operation is too troublesome, and many people don’t pay attention to that website, o((⊙﹏⊙))o.

Come on everyone ( •̀ ω •́ )y look forward to seeing you again