2022宁波市第五届网络安全大赛（初赛Misc部分）

听说线下决赛有菠萝包吃？

解题情况：5题解4，一个三血，哆哆嗦嗦进决赛

BlackAndWhite

打开附件，发现是黑色和白色照片，猜测代表2进制，一共336张

脚本如下

white = open('D:/Users/huawei/Desktop/target/0.png', 'rb').read()
black = open('D:/Users/huawei/Desktop/target/1.png', 'rb').read()
​
flag = ''
​
for i in range(336):
    color = open('D:/Users/huawei/Desktop/target/%d.png'%i, 'rb').read()
    if(color == white):
        flag += '0'
    else:
        flag += '1'
​
ans = ''
length = len(flag)//8
for i in range(length):
    ans += chr(int(flag[i*8: (i+1)*8], 2))
​
print(ans)
​

flag{baaf013d-f3fa-bcbe-00fb-1e1a34bb2af1}

Analyze

PDF文件

base64编码过

VGhlIHBhc3N3b3JkIGlzIG5vdCBqdXN0IGFib3V0IGRlY29kaW5nLCBidXQgYWxzbyBoYWNraW5nIHRoZSBaSVAh
解码之后
The password is not just about decoding, but also hacking the ZIP!

提示爆破，爆破出密码为cr4ck!*

成功解压

使用stegsolve打开图片

拿到flag

flag{abae93fb-c31f-aeaf-91fc-0f1d42ba26e4}

DocDocDoc

打开附件

D:\Users\huawei\Desktop\Hello Flag\word\media

这个路径下有两张图片

第二张图片，使用tweakpng修改高度为960

打开图片

pvkq{olp281m-m2pk-kmlo-81pl-2o2m08m0pmk1}

位移密码，key=10

flag{ebf281c-c2fa-acbe-81fb-2e2c08c0fca1}

Digtal_plate

流量包报错

提取usbdata脚本

#!/usr/bin/env python
# coding:utf-8
​
import sys
import os
import numpy as np
import matplotlib.pyplot as plt
​
mousePositionX = 0
mousePositionY = 0
​
X = []
Y = []
​
DataFileName = "usb.dat"
data = []
​
def main():
    global mousePositionX
    global mousePositionY
    # check argv
    if len(sys.argv) != 3:
        print  ("Usage : ")
        print ("        python UsbMiceHacker.py data.pcap [LEFT|RIGHT|MOVE|ALL]")
        print  ("Tips : ")
        print  ("        To use this python script , you must install the numpy,matplotlib first.")
        print  ("        You can use `sudo pip install matplotlib numpy` to install it")
        print  ("Author : ")
        print  ("        WangYihang ")
        print  ("        If you have any questions , please contact me by email.")
        print  ("        Thank you for using.")
        exit(1)
​
    # get argv
    pcapFilePath = sys.argv[1]
    action = sys.argv[2]
​
    if action != "LEFT" and action != "ALL" and action != "RIGHT" and action != "MOVE":
        action = "LEFT"
​
    # get data of pcap
    command = "tshark -r '%s' -T fields -e usbhid.data > %s" % (
        pcapFilePath, DataFileName)
    print (command)
    os.system(command)
​
    # read data
    with open(DataFileName, "r") as f:
        for line in f:
            data.append(line[0:-1])
​
    # handle move
    for i in data:
        Bytes = i.split(":")
        if len(Bytes) == 8:
            horizontal = 2  # -
            vertical = 4  # |
        elif len(Bytes) == 4:
            horizontal = 1  # -
            vertical = 2  # |
        else:
            continue
        offsetX = int(Bytes[horizontal], 16)
        offsetY = int(Bytes[vertical], 16)
        if offsetX > 127:
            offsetX -= 256
        if offsetY > 127:
            offsetY -= 256
        mousePositionX += offsetX
        mousePositionY += offsetY
        if Bytes[0] == "01":
            # print "[+] Left butten."
            if action == "LEFT":
                # draw point to the image panel
                X.append(mousePositionX)
                Y.append(-mousePositionY)
        elif Bytes[0] == "02":
            # print "[+] Right Butten."
            if action == "RIGHT":
                # draw point to the image panel
                X.append(mousePositionX)
                Y.append(-mousePositionY)
        elif Bytes[0] == "00":
            # print "[+] Move."
            if action == "MOVE":
                # draw point to the image panel
                X.append(mousePositionX)
                Y.append(-mousePositionY)
        else:
            # print "[-] Known operate."
            pass
        if action == "ALL":
            # draw point to the image panel
            X.append(mousePositionX)
            Y.append(-mousePositionY)
​
    fig = plt.figure()
    ax1 = fig.add_subplot(111)
​
    ax1.set_title('[%s]-[%s] Author : WangYihang' % (pcapFilePath, action))
    ax1.scatter(X, Y, c='r', marker='o')
    plt.show()
​
    # clean temp data
    os.system("rm ./%s" % (DataFileName))
​
if __name__ == "__main__":
    main()
​
​

发现是 数位板流量（前三位是088，后8位是八个0）

判断是数位板上画图

画图脚本

#!/usr/bin/env python
# coding:utf-8
​
import sys
import os
import numpy as np
import matplotlib.pyplot as plt
​
data=[]
with open("usbdata.txt","r") as f:
    for line in f.readlines():
            data.append(line)
X = []
Y = []
for line in data:
        x0=int(line[4:6],16)
        x1=int(line[6:8],16)
        x=x0+x1*256
        y0=int(line[8:10],16)
        y1=int(line[10:12],16)
        y=y0+y1*256
        X.append(x)
        Y.append(-y)
fig = plt.figure()
ax1 = fig.add_subplot(111)
ax1.set_title("key")
ax1.scatter(X, Y, c='r', marker='o')
plt.show()
​

画图结果如下

拿到一个key

kaseyd4wi2v3sc518dc84bsa4a96

binwalk -e 出来一个zip文件

解压密码就是上面那个

解压出一个图片

猜测是silenteye解密，解密失败

备注发现异常

写的太轻，提示到数位板画画的时候，会有压力感觉

看一下前面都有

0880应该是标识所以画点的数据应该在后面

有数值的是八位

所以x四位y四位

然后发现后面有0880，0881

两个都导出一下，0880是没按压，0881是按压，把0881为前缀的数据提取出来然后描点就行了

#!/usr/bin/env python
# coding:utf-8
# beizi
import matplotlib.pyplot as plt
import sys
import numpy as np
import os
​
data=[]
with open("usbhiddata.txt","r") as f:
    for line in f.readlines():
            data.append(line)
X = []
Y = []
for line in data:
        x0=int(line[4:6],16)
        x1=int(line[6:8],16)
        x=x0+x1*256
        y0=int(line[8:10],16)
        y1=int(line[10:12],16)
        y=y0+y1*256
        X.append(x)
        Y.append(-y)
fig = plt.figure()
ax1 = fig.add_subplot(111)
ax1.set_title("key")
ax1.scatter(X, Y, c='r', marker='o')
plt.show()

提取带有压感的流量数据，画图得到

18cba496

作为key，使用slienceeye解密

flag{42a12187c01a4a4f2b3f5ccd0a019656}