Network Attacks

NETWORK ATTACKS
Attacks on network

Attacking a network means either defacing it to ground or accessing a data which
you should not. In a network there are mainly two types of attacks are possible.
1). Denial of Service (DOS) attack.
2). Data Stealing.
network-infrastructure attacks
Hacker attacks against network infrastructures can be easy, because many
networks can be reached from anywhere in the world via the Internet. Here are some examples of network-infrastructure attacks: Connecting into a network through a rogue modem attached to a computer behind
a firewall Exploiting weaknesses in network transport mechanisms, such as TCP/IP and NetBIOS Flooding a network with too many requests, creating a denial of service (DoS)
for legitimate requests installing a network analyzer on a network and capturing every packet that travels across it, revealing confidential information in clear text.
common network attacks

1) Sniffing Attack.
2) Man in middle attack.
3) DOS attacks.
sniffing attacks

Sniffers monitor network data. A sniffer can be a self-contained software program or a hardware device with
the appropriate software or firmware programming.
Sniffers usually act as network probes or "snoops" examining network traffic but
not intercepting or altering it. Some sniffers work only with TCP/IP packets, but the more sophisticated tools can work with many other protocols and at lower levels such as the Ethernet frame.
concept

A sniffer is a piece of software that captures the traffic on a network. They are available for
several platforms in both commercial and open-source variations. Some of simplest packages use a command line interface and dump captured data to the screen, while sophisticated ones use GUI, graph traffic statistics, track multiple sessions and offer several configuration options.
Sniffers are also the engines for other programs. Network Intrusion Detection Systems (NIDS)
use sniffers to match packets against a rule-set designed to flag anything malicious or strange. Network utilization and monitoring programs often use sniffers to gather data necessary for metrics and analysis. It is to be noted that sniffers do not intercept or alter the data it captures.
The most common way of networking computers is through Ethernet. The Ethernet protocol works by broadcasting packets to all
hosts on the network, with the packet header containing the MAC address of the machine that is meant to receive the packet. All others are supposed to ignore it. A NIC (Network Interface Card, also known as Ethernet card) that is accepting all packets, regardless of the intended machine is said to be in promiscuous mode. A sniffer is a program that sets the desired NIC into promiscuous mode.
note
A packet sniffer is known for its ability to "sniff" plain text passwords. On a normal LAN there are thousands
of packets being conversed by numerous machines every minute. Therefore, anything transmitted in plaintext, such as passwords, web pages, database queries and messaging over the network will be vulnerable to sniffing. man in the middle