python 检查是否存在ddos攻击

!/usr/bin/python

coding=utf-8

import dpkt import socket import optparse

默认设置检测不正常数据包的数量的阈值为1000

THRESH = 1000

def findDownload(pcap): for (ts, buf) in pcap: try: eth = dpkt.ethernet.Ethernet(buf) ip = eth.data src = socket.inet_ntoa(ip.src) # 获取TCP数据 tcp = ip.data # 解析TCP中的上层协议HTTP的请求 http = dpkt.http.Request(tcp.data) # 若是GET方法，且请求行中包含“.zip”和“loic”字样则判断为下载LOIC if http.method == 'GET': uri = http.uri.lower() if '.zip' in uri and 'loic' in uri: print "[!] " + src + " Downloaded LOIC." except: pass

def findHivemind(pcap): for (ts, buf) in pcap: try: eth = dpkt.ethernet.Ethernet(buf) ip = eth.data src = socket.inet_ntoa(ip.src) dst = socket.inet_ntoa(ip.dst) tcp = ip.data dport = tcp.dport sport = tcp.sport # 若目标端口为6667且含有“!lazor”指令，则确定是某个成员提交一个攻击指令 if dport == 6667: if '!lazor' in tcp.data.lower(): print '[!] DDoS Hivemind issued by: '+src print '[+] Target CMD: ' + tcp.data # 若源端口为6667且含有“!lazor”指令，则确定是服务器在向HIVE中的成员发布攻击的消息 if sport == 6667: if '!lazor' in tcp.data.lower(): print '[!] DDoS Hivemind issued to: '+src print '[+] Target CMD: ' + tcp.data except: pass

def findAttack(pcap): pktCount = {} for (ts, buf) in pcap: try: eth = dpkt.ethernet.Ethernet(buf) ip = eth.data src = socket.inet_ntoa(ip.src) dst = socket.inet_ntoa(ip.dst) tcp = ip.data dport = tcp.dport # 累计各个src地址对目标地址80端口访问的次数 if dport == 80: stream = src + ':' + dst if pktCount.has_key(stream): pktCount[stream] = pktCount[stream] + 1 else: pktCount[stream] = 1 except: pass

for stream in pktCount:
    pktsSent = pktCount[stream]
    # 若超过设置检测的阈值，则判断为进行DDoS攻击
    if pktsSent > THRESH:
        src = stream.split(':')[0]
        dst = stream.split(':')[1]
        print '[+] ' + src + ' attacked ' + dst + ' with ' + str(pktsSent) + ' pkts.'

def main(): parser = optparse.OptionParser("[*]Usage python findDDoS.py -p <pcap file> -t <thresh>") parser.add_option('-p', dest='pcapFile', type='string', help='specify pcap filename') parser.add_option('-t', dest='thresh', type='int', help='specify threshold count ') (options, args) = parser.parse_args() if options.pcapFile == None: print parser.usage exit(0) if options.thresh != None: THRESH = options.thresh pcapFile = options.pcapFile # 这里的pcap文件解析只能调用一次，注释掉另行修改 # f = open(pcapFile) # pcap = dpkt.pcap.Reader(f) # findDownload(pcap) # findHivemind(pcap) # findAttack(pcap) with open(pcapFile, 'r') as f: pcap = dpkt.pcap.Reader(f) findDownload(pcap) with open(pcapFile, 'r') as f: pcap = dpkt.pcap.Reader(f) findHivemind(pcap) with open(pcapFile, 'r') as f: pcap = dpkt.pcap.Reader(f) findAttack(pcap)

if name == 'main': main()

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