一、MISC 我的心是冰冰的

描述：似乎有資訊被隱藏了，

1>.首先，思路是盲猜用圖中的資訊解壓縮包的密碼
另一邊用zip爆破工具爆破，節省時間，爆破居然先爆破出來了
密碼是：gnibgnib

2>.然后分析bingbing.pcapng
打開后發現是usb鍵盤流量，或者是usb滑鼠流量
網上查資料可得，USB協議的資料部分在Leftover Capture Data域之中，右鍵leftover capture data –> 應用為列，可以將該域的值在主面板上顯示，鍵盤資料包的資料長度為8個位元組，擊鍵資訊集中在第3個位元組，每次key stroke都會產生一個keyboard event usb packet

可以將 leftover capture data單獨提取出來，在linux中，具體命令為：tshark -r bingbing.pcap -T fields -e usb.capdata > usbdata.txt

因此，這就是usb鍵盤流量

3.從得出的userdata.txt檔案中過濾出鍵盤擊鍵相關的流量，并根據映射表，將鍵盤按鍵按照對應關系輸出出來，查資料找到了網上的腳本

#!/usr/bin/env python
import sys
import os

DataFileName = "usbdata.txt"

presses = []

normalKeys = {"04":"a", "05":"b", "06":"c", "07":"d", "08":"e", "09":"f", "0a":"g", "0b":"h", "0c":"i", "0d":"j", "0e":"k", "0f":"l", "10":"m", "11":"n", "12":"o", "13":"p", "14":"q", "15":"r", "16":"s", "17":"t", "18":"u", "19":"v", "1a":"w", "1b":"x", "1c":"y", "1d":"z","1e":"1", "1f":"2", "20":"3", "21":"4", "22":"5", "23":"6","24":"7","25":"8","26":"9","27":"0","28":"<RET>","29":"<ESC>","2a":"<DEL>", "2b":"\t","2c":"<SPACE>","2d":"-","2e":"=","2f":"[","30":"]","31":"\\","32":"<NON>","33":";","34":"'","35":"<GA>","36":",","37":".","38":"/","39":"<CAP>","3a":"<F1>","3b":"<F2>", "3c":"<F3>","3d":"<F4>","3e":"<F5>","3f":"<F6>","40":"<F7>","41":"<F8>","42":"<F9>","43":"<F10>","44":"<F11>","45":"<F12>"}

shiftKeys = {"04":"A", "05":"B", "06":"C", "07":"D", "08":"E", "09":"F", "0a":"G", "0b":"H", "0c":"I", "0d":"J", "0e":"K", "0f":"L", "10":"M", "11":"N", "12":"O", "13":"P", "14":"Q", "15":"R", "16":"S", "17":"T", "18":"U", "19":"V", "1a":"W", "1b":"X", "1c":"Y", "1d":"Z","1e":"!", "1f":"@", "20":"#", "21":"$", "22":"%", "23":"^","24":"&","25":"*","26":"(","27":")","28":"<RET>","29":"<ESC>","2a":"<DEL>", "2b":"\t","2c":"<SPACE>","2d":"_","2e":"+","2f":"{","30":"}","31":"|","32":"<NON>","33":"\"","34":":","35":"<GA>","36":"<","37":">","38":"?","39":"<CAP>","3a":"<F1>","3b":"<F2>", "3c":"<F3>","3d":"<F4>","3e":"<F5>","3f":"<F6>","40":"<F7>","41":"<F8>","42":"<F9>","43":"<F10>","44":"<F11>","45":"<F12>"}

def main():
    # check argv
    if len(sys.argv) != 2:
        print "Usage : "
        print "        python UsbKeyboardHacker.py data.pcap"
        print "Tips : "
        print "        To use this python script , you must install the tshark first."
        print "        You can use `sudo apt-get install tshark` to install it"
        print "Author : "
        print "        Angel_Kitty <angelkitty6698@gmail.com>"
        print "        If you have any questions , please contact me by email."
        print "        Thank you for using."
        exit(1)

    # get argv
    pcapFilePath = sys.argv[1]
    
    # get data of pcap
    os.system("tshark -r %s -T fields -e usb.capdata > %s" % (pcapFilePath, DataFileName))

    # read data
    with open(DataFileName, "r") as f:
        for line in f:
            presses.append(line[0:-1])
    # handle
    result = ""
    for press in presses:
        Bytes = press.split(":")
        if Bytes[0] == "00":
            if Bytes[2] != "00":
                result += normalKeys[Bytes[2]]
        elif Bytes[0] == "20": # shift key is pressed.
            if Bytes[2] != "00":
                result += shiftKeys[Bytes[2]]
        else:
            print "[-] Unknow Key : %s" % (Bytes[0])
    print "[+] Found : %s" % (result)

    # clean the temp data
    os.system("rm ./%s" % (DataFileName))


if __name__ == "__main__":
main()

最后結果從 DEL 分段分別解密文， 16進制解碼即可
flag值： flag{8f9ed2f933ef14a8d0523d0349e1299c}

總結：挺有勁兒的一題，做了好久，明明答案早已經出來了，開始卻沒發現那是16進制，輾轉了好久，以為是腳本錯了，折騰好久，最后才想到答案可能是密文，提交答案時卻是第10名提交的，錯失前三血嗚嗚嗚

二、簽到

MISC 簽到
答對8道資料安全知識小競賽題，得flag

flag值： flag{7e63095d-4310-4f24-a01a-4a858d442fab}

賽后感受：小白做題，難得一批，題目好多不會做，還是很自閉了，感謝隊友的輔助，一起加油！