USB流量分析
USB接口是目前最为通用的外设接口之一，通过监听该接口的流量，可以得到很多有意思的东西，例如键盘击键，鼠标移动与点击，存储设备的明文传输通信、USB无线网卡网络传输内容等。
1、USB流量的捕获
USB流量的捕获可以使用wireshark自带的工具usbpcap来进行
安装wirshark时勾选上安装usbpcap即可
1.鼠标流量
抓包
鼠标移动的轨迹，右键，左键的行为都能捕捉到
(这里有个坑，有的鼠标可能协议不标准、抓到的数据分析不了)
保存为pacp文件
USB协议的数据部分在Leftover Capture Data域之中，在Linux下可以用tshark命令可以将 leftover capture data单独提取出来 命令如下：
tshark -r 7777.pcapng -T fields -e usb.capdata > usbdata.txt
运行命令并查看usbdata.txt 发现数据包长度为八个字节
写出解密脚本
nums = []
keys = open('usb.txt','r')
posx = 0
posy = 0
for line in keys:
if len(line) != 12 :
continue
x = int(line[3:5],16)
y = int(line[6:8],16)
if x > 127 :
x -= 256
if y > 127 :
y -= 256
posx += x
posy += y
btn_flag = int(line[0:2],16) # 1 for left , 2 for right , 0 for nothing
if btn_flag == 1 :
print posx , posy
keys.close()
当btn_flag 取1时 对应鼠标左键、2对应鼠标右键
运行脚本可以得到一系列坐标点
得到这些点之后，需要将他们画出来，因而需要辅以gnuplot 或者其他的绘图工具，gnuplot的命令为"plot inputfile"，运行如下：
使用一航大佬的工具
键盘流量
一样的抓包方式
确定为键盘流量后
tshark -r 1111.pcapng -T fields -e usb.capdata > usbdata.txt脚本
#!/usr/bin/env python
# -*- coding:utf-8 -*-
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":"","29":"","2a":"", "2b":"\t","2c":"","2d":"-","2e":"=","2f":"[","30":"]","31":"\\","32":"","33":";","34":"'","35":"","36":",","37":".","38":"/","39":"","3a":"","3b":"", "3c":"","3d":"","3e":"","3f":"","40":"","41":"","42":"","43":"","44":"","45":""}
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":"","29":"","2a":"", "2b":"\t","2c":"","2d":"_","2e":"+","2f":"{","30":"}","31":"|","32":"","33":"\"","34":":","35":"","36":"<","37":">","38":"?","39":"","3a":"","3b":"", "3c":"","3d":"","3e":"","3f":"","40":"","41":"","42":"","43":"","44":"","45":""}
output = []
keys = open('usbdata.txt')
for line in keys:
try:
if line[0]!='0' or (line[1]!='0' and line[1]!='2') or line[3]!='0' or line[4]!='0' or line[9]!='0' or line[10]!='0' or line[12]!='0' or line[13]!='0' or line[15]!='0' or line[16]!='0' or line[18]!='0' or line[19]!='0' or line[21]!='0' or line[22]!='0' or line[6:8]=="00":
continue
if line[6:8] in normalKeys.keys():
output += [[normalKeys[line[6:8]]],[shiftKeys[line[6:8]]]][line[1]=='2']
else:
output += ['[unknown]']
except:
pass
keys.close()
flag=0
print("".join(output))
for i in range(len(output)):
try:
a=output.index('')
del output[a]
del output[a-1]
except:
pass
for i in range(len(output)):
try:
if output[i]=="":
flag+=1
output.pop(i)
if flag==2:
flag=0
if flag!=0:
output[i]=output[i].upper()
except:
pass
print ('output :' + "".join(output))
直接使用大佬的工具
参考链接：
https://www.jianshu.com/p/92064f2e9dcb
https://www.anquanke.com/post/id/85218
工具
https://ctf-wiki.github.io/ctf-wiki/misc/traffic/protocols/USB/