What is IP Spoofing?

Internet Protocol (IP) spoofing is a malicious attack in which a threat actor conceals the true source of IP packets, making it challenging to determine where they originated.

The attacker produces packets by modifying the source IP address to mimic another computer system, conceal the sender’s identity, or both. The faked packet’s header field for the source IP address contains a different address from the genuine source IP address.

IP spoofing is a common technique attackers use to execute distributed denial-of-service (DDoS) and man-in-the-middle attacks on targeted devices or infrastructures. The purpose of DDoS assaults is to overwhelm a target with traffic while concealing the identity of the malicious source, hence thwarting mitigation efforts.

Using faked IP addresses, attackers can do the following:

1. Prevent police from finding who they are and blaming them for the attack.
2. Prevent targeted devices from issuing notifications about assaults in which they are unwitting participants.
3. Avoid security scripts, devices, and services that block IP addresses known to send malicious traffic.

How does IP spoofing work? 

Packets are the units in which Internet traffic is sent. Packets have IP headers, which include routing information. This information covers the source and destination IP addresses. Consider the packet a mail package, with the source IP address as the package’s return address.

In IP address spoofing, the attacker modifies the source address in the outgoing packet headers. This way, the destination computer recognises the packet as originating from a trusted source, such as a computer on a business network, and accepts it.

Attackers can create fraudulent packet headers by fabricating and repeatedly randomising the source address with a tool. They may even use another device’s IP address to redirect responses to the faked packet.

To do IP spoofing, attackers require the following:

1. A trusted IP address that the receiving device will allow to enter the network. There are several techniques to obtain device IP addresses. One option is Shodan, an online database of IP address-to-device mappings.
2. The second requirement is intercepting a packet and replacing the apparent IP header with a fake one. An Address Resolution Protocol (ARP) scan or a network sniffing tool can seize network packets and gather IP addresses for spoofing.

How can you detect IP spoofing? 

End consumers have difficulty identifying IP spoofing. These assaults occur at the network layer. That way, there are no visible traces of meddling. From the outside, the fraudulent connection requests appear to be authentic.

However, enterprises can employ network monitoring tools to analyse traffic at network endpoints. The most common method for accomplishing this is through packet filtering.

Packet filtering systems are commonly found in routers and firewalls. They detect discrepancies between the packet’s IP address and the desired IP addresses on access control lists (ACLs). They also identify counterfeit packets.

There are two forms of packet filtering: ingress and egress filtering.

Ingress filtering checks incoming packets to see whether the source IP header matches an allowed source address. It rejects any that do not match or exhibit suspicious behaviour. This filtering creates an ACL with acceptable source IP addresses.

Egress filtering analyses outgoing traffic, scanning for source IP addresses that do not correspond to those on the company’s network. This strategy stops insiders from carrying out an IP spoofing attack.

How can you prevent IP spoofing? 

IP faked packets cannot be deleted. However, corporations can take precautions to safeguard their networks and data.

Companies can take the following steps:

1. Use robust verification and authentication techniques for every remote access. Do not authenticate devices or users purely based on their IP addresses.
2. Create an ACL of IP addresses.
3. Use entrance and egress packet filtering.
4. Use antivirus and other security tools to monitor suspicious network activities.
5. Use IP-level encryption to secure communication to and from the business server. This strategy prevents attackers from reading potential IP addresses to impersonate.
6. Keep network software up-to-date and use proper patch management.
7. Continuous network monitoring.

Firewalls and enterprise router filtering rules should be set to reject packets that could be faked. This would include packets with private IP addresses sent from beyond the enterprise border. It also includes traffic that originates within the company but uses an external address as the originating IP address. This prevents spoofing attacks from being launched from the internal network onto external networks.

What are some examples of IP spoofing? 

When attackers conduct a DDoS attack, they use spoofed IP addresses to flood computer systems with too massive packets for the destination computers to process. Botnets are frequently used to send geographically distributed packets. Large botnets may consist of tens of thousands of machines, each capable of simultaneously spoofing many source IP addresses. These automated attacks are challenging to track.

How can iZOOlogic help my Company or Organisation?

Find out how iZOOlogic can protect your infrastructure from IP spoofing attacks through our Incident Response solutions under our Threat Management Services.

To find out more about how iZOOlogic can help protect your company’s cyber security, schedule a demo.