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NMAP. ANA MARIA CHANABA ROBERT HUYLO. HOW TO HIDE IP ADDRESS. Decoy scanning can be used to effectively confuse the intended target.
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NMAP • ANA MARIA CHANABA • ROBERT HUYLO
HOW TO HIDE IP ADDRESS • Decoy scanning can be used to effectively confuse the intended target. • Basically you are sending spoofed packets with a fake source address along with your original address hoping to make it harder to find out exactly who is scanning them. • nmap -sS -D ( IP address of multiple host) • nmap sends four packets each from a different source address.
DECOYS • What is the point of sending four TCP SYN packets? • The reason is to hide the real IP address in a mass of foreign addresses. Making it more difficult to detect the real attacker. • Another thing to note is the more decoys the slower the scan.
DECOY • The decoy address will be receiving either RESET ICMP Port Unreachable if the port is closed and SYN ACK packets if the port is open. • When the host name is specified, the real IP will show up on the DNS server of the decoy. • This technique requires an attacker to send some packets to the target from her real IP address. On the other hand, Idle scan does not send any packets.
DECOY: NMAP AND SNORT TWO SIDES OF THE SAME COIN • Nmap is a port scanner, which can search a target computer for open ports, and thus for potential security loopholes. • Snort’s task is to counteract nmap. Snort is a daemon which scans through a network for suspect packages and logs them. • IP might set of more warnings in snort than the decoys. • The real attackers IP in a decoy scan always shows up first in the snort alert log.
IP’S SHOW UP IN A SNORT LOG • SENT (0.0060s) ICMP 192.168.0.4 > 192.168.0.3 Echo request (type=8/code=0) ttl=42 id=2717 iplen=28SENT (0.0070s) ICMP 192.168.0.7 > 192.168.0.3 Echo request (type=8/code=0) ttl=58 id=27663 iplen=28SENT (0.0070s) ICMP 192.168.0.1 > 192.168.0.3 Echo request (type=8/code=0) ttl=41 id=3618 iplen=28RCVD (0.0070s) ICMP 192.168.0.3 > 192.168.0.4 Echo reply (type=0/code=0) ttl=64 id=37318 iplen=28 • [**] [1:469:1] ICMP PING NMAP [**][Classification: Attempted Information Leak] [Priority: 2]07/23-18:46:13.256183 192.168.0.4 -> 192.168.0.3ICMP TTL:42 TOS:0x0 ID:2717 IpLen:20 DgmLen:28Type:8 Code:0 ID:53476 Seq:52818 ECHO[Xref => http://www.whitehats.com/info/IDS162][**] [1:469:1] ICMP PING NMAP [**][Classification: Attempted Information Leak] [Priority: 2]07/23-18:46:13.256190 192.168.0.7 -> 192.168.0.3ICMP TTL:58 TOS:0x0 ID:27663 IpLen:20 DgmLen:28Type:8 Code:0 ID:53476 Seq:52818 ECHO[Xref => http://www.whitehats.com/info/IDS162]
-sI Idlescan • Completely “blind” scanning - no packets are sent to target from machine running nmap • Uses another host (“zombie”), to bounce packets to target • Can reveal IP-based trust relationships