Nmap Xmas scan was considered a
stealthy scan which analyzes responses to Xmas packets to determine the nature of the replying device
. Each operating system or network device responds in a different way to Xmas packets revealing local information such as OS (Operating System), port state and more.
What is a Xmas scan used for?
An adversary uses a TCP XMAS scan
to determine if ports are closed on the target machine
. This scan type is accomplished by sending TCP segments with all possible flags set in the packet header, generating packets that are illegal based on RFC 793.
What is Xmas tree scan?
Christmas tree packets can be used as
a method of TCP/IP stack fingerprinting
, exposing the underlying nature of a TCP/IP stack by sending the packets and then awaiting and analyzing the responses. When used as part of scanning a system, the TCP header of a Christmas tree packet has the flags FIN, URG and PSH set.
What type of packets does an Xmas scan send?
XMAS – XMAS scans send a packet with
the FIN, URG, and PSH flags set
. If the port is open, there is no response; but if the port is closed, the target responds with a RST/ACK packet. XMAS scans work only on target systems that follow the RFC 793 implementation of TCP/IP and don’t work against any version of Windows.
What is decoy scan in nmap?
nmap has -D option. It is called decoy scan. With -D option it appear to the remote host that the host(s) you specify as
decoys are scanning the target network too
. Thus their IDS might report 5-10 port scans from unique IP addresses, but they won’t know which IP was scanning them and which were innocent decoys.
Why are null FIN and Xmas scans used?
The NULL, FIN, and Xmas scans
clear the SYN bit and thus fly right through
those rules. Another advantage is that these scan types are a little more stealthy than even a SYN scan.
What is a TCP ACK scan?
The TCP ACK scanning technique
uses packets with the flag ACK on to try to determine if a port is filtered
. This technique comes handy when checking if the firewall protecting a host is stateful or stateless.
Which Nmap flag can be used for Xmas tree scan?
In the Xmas scan, Nmap sends
packets with URG, FIN, and PSH flags
activated. This has the effect of “lighting the packet up like a Christmas tree” and can occasionally solicit a response from a firewalled system. Not all systems will respond to probes of this type.
What is a stealth scan?
A stealth scan (sometimes known as a half open scan) is
much like a full open scan with a minor difference that makes it less suspicious on the victim’s device
. The primary difference is that a full TCP three-way handshake does not occur.
How does a FIN scan work?
The FIN scan
sends a packet that would never occur in the real world
. It sends a packet with the FIN flag set without first establishing a connection with the target. … Again, if no packet is received, the port is considered open and if a RST packet is received, the port is considered closed.
What is the proper command to perform an nmap XMAS scan?
Nmap Xmas Scan can be performed using
nmap -sX command
.
Why would an attacker want to perform a scan on port 137?
from their windows machine and collect information about your windows machine
(if you are not blocking traffic to port 137 at your borders). …
How would you tell Nmap to scan all ports?
By default, Nmap scans
the 1,000 most popular ports of each protocol it
is asked to scan. Alternatively, you can specify the -F (fast) option to scan only the 100 most common ports in each protocol or –top-ports to specify an arbitrary number of ports to scan.
Are Nmap scans detectable?
Can Nmap scans be detected? Usually
only scan types that establish full TCP connections are logged
, while the default Nmap SYN scan sneaks through. Intrusive scans, particularly those using Nmap version detection, can often be detected this way. But only if the administrators actually read the system logs regularly.
What does idle scanning do?
The idle scan is a TCP port scan method that consists
of sending spoofed packets to a computer to find out what services are available
. This is accomplished by impersonating another computer whose network traffic is very slow or nonexistent (that is, not transmitting or receiving information).
What is IP spoofing?
IP spoofing is
the creation of Internet Protocol (IP) packets which have a modified source address in order to either hide the identity of the sender
, to impersonate another computer system, or both.
