There are different types of network attacks that can harm computer network. The network attacks are classified into three main categories which are following:
- Reconnaissance attacks
- Access attacks
- Denial of service
The attackers use internet tool for the reconnaissance attack, such as the whois and nslookup, to resolve the IP address of the host or the organization. Once the attacker resolves the IP address, then he can ping the public addresses to identify the address that is active. The attacker also can use ping sweep tool such as fping and gping that automatically pings addresses in the given range. The attacker can also use port scan and packet sniffing.
the unauthorized manipulation of data, system access, or user privileges
This type of attack use vulnerabilities in the operating system authentication service; web and FTP services to get access to different types of account such as web account; databases and information services. This attack allows attackers unauthorized access to information that the attacker have no rights. The access attacks are classified into four types:
- Password attacks – The attackers use a different technique to get a password of the users, such as packet sniffers, Brute-force-attack and Trojan horse.
- Trust Exploitation – For this type of access attacks, the attacker can use active directory services and network files systems.
- Port Redirection – In this type of attack the attackers used compromised computer ports to get access on another computer on the network.
- Man-in-the-Middle – in this type of attack the attacker inter between the server and client.
Denial of Service Attacks
Denial of Service (DoS) attacks is the most difficult attack to avoid and eliminate. DoS attacks are required so little effort to execute but it is too damaging than other types of attacks. So DoS attacks need special attention from network security administrators. The DoS attack has many forms, to help prevent DoS attacks it is important to systems with the latest security update for operating system and application.
The Dos attacks prevent authorized peoples from using a service by using up system resources. following are some types of DoS attacks
- Disk space, bandwidth, buffers overloading
- Ping floods such as smurf
- Packet storms like UDP bombs and Fraggle
- Oversized packets such as ping of death
- Overlapping packet like winuke
- Unhandled data such as teardrop.