攻防世界misc——picture2

下载附件，很普通的一张图片

010和Stegsolve看不出问题，上binwalk

得到两个文件，在名为“97E4”的文件中发现base64加密的字符串

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

直接base64解码

出现乱码，以及部分python代码报错提示

上面看见KP开头，怀疑是zip格式文件，直接写出文件

import java.io.FileOutputStream;
import java.util.Base64;

/**
 * @Author: Jack Jparrow
 * @Date: 2022-01-13 15:07:51
 * @LastEditTime: 2022-01-13 15:13:36
 * @LastEditors: Jack Jparrow
 * @Description: base64转字符，发现是zip文件，直接保存出错，转byte，再写出为zip文件
 */

public class picture2 {

    public static void main(String[] args) {
        try {
            String str = "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";

            Base64.Decoder de = Base64.getDecoder();

            // byte[] b = new String(de.decode(str)).getBytes();// 转Sting文件会出错
            byte[] c = de.decode(str);

            FileOutputStream out = new FileOutputStream("D:\\Desktop\\3.zip");

            out.write(c);
            out.flush();
            out.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

010把前面改成504B

解压，要密码

根据提示，密码是py2.7的一个报错提示

经过百度，得知该提示为integer division or modulo by zero

解压得到加密过的字符串

根据其特征begin xxxx，得知为UUencode编码，解码得到flag：

——————分割线——————

关于UUencode