IP Spoofing

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IP Spoofing Definition

Spoofing is a type of cyber-attack in which the attacker uses a device or network to trick other computer networks into believing they are a legitimate entity to take over the devices themselves as zombies for malicious use, gain access to sensitive data, or launch Denial-of-Service (DoS) attacks. IP spoofing is the most common type of spoofing.

Sometimes called Internet Protocol (IP) spoofing or IP address spoofing, IP spoofing refers to impersonating another computer system by creating IP packets with false source IP addresses. IP spoofing detection can often be difficult. This is because IP spoofing allows cybercriminals to engage in malicious activity such as infecting a device with malware, stealing data, or crashing a server, without detection.

Attackers often engage in IP spoofing to target devices with man-in-the-middle attacks and distributed denial of service (DDoS) attacks, as well as their surrounding infrastructures. The goal of DoS attacks and IP spoofing attacks is to flood a target with traffic and overwhelm it, while preventing mitigation efforts by hiding the identity of the attack source.

Attackers spoofing an IP address can:

  • Prevent security teams and authorities from identifying them and tying them to the attack;
  • Stop targeted devices from alerting users to attacks, making them unwitting participants; and
  • Avoid security devices, scripts, and services that blocklist IP addresses that are malicious traffic sources.

Image depicts attacker computer using IP spoofing to attack victim.

IP Spoofing FAQs

What is IP Spoofing?

What is IP spoofing and how can it be prevented? When users transmit data over the internet, it is first broken into multiple units called packets. The packets travel independently and at the end, the receiving system reassembles them. Packets contain IP headers with routing information including the source IP address and the destination IP address. The packet is similar to a package in transit with its return address represented by the source IP address.

In IP address spoofing, a hacker modifies the source address in the packet header with basic IP spoofing tools so the receiving system thinks the packet is from a trusted source, such as a device on a legitimate enterprise network, and accepts it. There is no trace of tampering, because IP spoofing works at the network level.

To engage in IP spoofing, hackers need only a trusted IP address and the ability to intercept packets and replace authentic IP headers with fraudulent versions. Traditional “castle and moat” network defense structures are highly vulnerable to IP spoofing and other attacks that prey on trusted relationships.

Although identity theft and online fraud or cybercriminals attacking corporate servers and websites are the most common examples of IP spoofing, it also has legitimate applications. For example, before websites live, organizations may use IP spoofing tests to ensure the site can handle volume without being overwhelmed. This kind of IP spoofing is not illegal.

Types of IP Spoofing

Among the most common IP spoofing techniques are:

Distributed Denial of Service (DDoS) attacks

In a DDoS attack, hackers overwhelm computer servers with packets of data using spoofed IP addresses. This enables them to hide their identity while slowing down or crashing a network or site with massive amounts of traffic.

Masking botnet devices

A botnet is a network of devices controlled by a hacker from a single location using IP spoofing software. Cybercriminals obtain access to computers by IP spoofing and masking botnets. Each bot in the network has a spoofed IP address, so IP spoofing allows the attacker to mask the botnet without being traced, maximizing their rewards by prolonging the duration of an attack.

Man-in-the-middle attacks

A ‘man-in-the-middle’ attack is another malicious IP spoofing technique. This method interrupts two devices as they communicate, alters the packets, and transmits them without either sender or receiver knowing. By spoofing an IP address and accessing personal accounts, attackers can direct users to fake websites, steal information, and more, making man-in-the-middle attacks highly lucrative.

MAC spoofing vs IP spoofing

MAC spoofing attacks take place when malicious clients use MAC addresses that do not belong to them to generate traffic. The goal is the ability to gain access or get past access control based on MAC information.

IP spoofing attacks are similar to MAC spoofing attacks, but the client uses an IP address. The goal is to harm both the initial target and innocent bystanders by prompting the initial target destination IP address to reply to as many source IP addresses as it can—replies the attacker never sees, since the source IP addresses are spoofed.

IP spoofing vs VPN

A VPN is itself a kind of IP spoofing service. It encrypts the user’s internet connection to protect the sensitive data being sent and received. So although the traditional use case for the VPN we think of here is to protect users from those who want to spy on our IP addresses—for any reason—they can also be used to spoof location.

What is AWS IP spoofing protection?

Amazon EC2 instances are protected by host-based, AWS-controlled firewall infrastructure that will not allow them to send spoofed network traffic with a source MAC or IP address other than its own.

Why is IP Spoofing Important?

IP spoofing is important to prepare for principally because it is difficult to detect. Victims often learn of it too late, as it happens before malicious actors initiate communication with them or attempt to access the target network.

Some of the main reasons IP spoofing can be difficult to detect and prevent include:

Easier to conceal than phishing. A successful spoof merely redirects the transaction or communication to a spoofed IP address and away from a legitimate receiver—there are no signs as there are with phishing.

Evades security. IP spoofing can bypass perimeter security and firewalls to disrupt the system and flood the network.

Extended concealment. A spoofed IP enables hackers to gain access as trusted users and hide inside vulnerable systems for extended periods of time.

More remote connections. The shift to remote work ensures that greater numbers of devices and users are connecting to the network, increasing the risk of IP spoofing greatly.

How to Detect IP Spoofing

How is IP address spoofing detected? For end users, detecting IP spoofing is difficult. There are no external signs of tampering because these attacks are carried out on Layer 3 or the network layer of the Open Systems Interconnection communications model. This allows spoofed connection requests to externally resemble legitimate connection requests.

However, organizations can perform traffic analysis with network monitoring tools at network endpoints. Packet filtering systems, frequently contained in firewalls and routers, are the primary way to do this. Packet filtering systems detect fraudulent packets and refer to access control lists (ACLs) to detect inconsistencies between the desired IP addresses on the list and the packet’s IP address.

Packet filtering includes two types: ingress and egress filtering.

  • Ingress filtering examines the source IP headers of incoming packets to confirm they match a permitted source address. Those that don’t match or exhibit any other behavior that is suspicious the system rejects. This filtering process establishes an ACL of source IP addresses the system permits.
  • Egress filtering, intended to prevent IP spoofing attacks launched by insiders, searches outgoing IT scans for source IP addresses that don’t match the company network.

How to Prevent IP Spoofing

IP spoofing attacks are difficult to spot, designed to conceal the identity of attackers. Server-side teams have the task of doing what they can to prevent IP spoofing. IP spoofing protection for IT specialists includes:

Monitoring. Monitor networks for unusual activity.
Packet filtering. Detect inconsistencies with packet filtering—for example, outgoing packets with source IP addresses that don’t match the network.
Verification. Deploy robust verification methods, including on the network.
Authentication. Authenticate all IP addresses with a network attack blocker.
Firewalls and IP spoofing. Placing some or all computing resources behind an IP spoofing firewall.

IP spoofing protection for end users is more hit and miss, because technically speaking, end-users can’t prevent IP spoofing. However, end users can minimize risk by engaging in best practices for cyber hygiene that ensure optimal online security:

  • Use strong authentication and verification methods for all remote access. Do not authenticate users or devices based solely on IP address.
  • Ensure secure system passwords and change default usernames and passwords to strong versions that contain at least 12 characters and a mix of numbers, upper- and lower-case letters, and symbols.
  • Be cautious on public Wi-Fi networks and avoid sharing sensitive information or conducting banking, shopping, or other financial transactions over unsecured public Wi-Fi. Use a VPN to stay safer if you do need to use public hotspots.
  • Use antivirus software and other security software that monitors suspicious network activity.
  • Use encryption protocols to protect all traffic to and from the server.
  • Visit HTTPS sites that encrypt data with an up-to-date SSL certificate, so users are less vulnerable to attacks. Sites with URLs that start HTTP instead of HTTPS are not secure; look for the padlock icon in the URL address bar.
  • Update and patch network software.
  • Watch for phishing attempts and use comprehensive antivirus protection to guard against viruses, hackers, malware, and other online threats. It’s also essential to keep your software up-to-date to ensure it has the latest security features.
  • Performing ongoing network monitoring.

Other Types of Network Spoofing

There are various types of spoofing, and some of them happen on IP-based networks, but most do not change the IP addresses of packets, so they are not IP address spoofing. Some other types of spoofing types that still involve IP addresses include:

An address resolution protocol or ARP spoofing vs IP spoofing attack occurs when an attacker spoofs and sends false ARP messages rather than packets. In this case, the attack happens over a local area network (LAN) at the data link layer and links the media access control address of the attacker to a legitimate IP address of a server or computer on the network.

In a domain name system (DNS) spoofing attack, the attacker alters DNS records rather than packets to divert internet traffic toward fake servers and away from legitimate sites.

Other types of spoofing may not affect IP addresses at all, or at least not directly:

Caller ID spoofing alters a caller ID display to make a phone call appear to originate from a different location.

Email spoofing alters email header fields to show a different sender and is often used in phishing attacks.

Global positioning system (GPS) spoofing allows the user of a device to trick it into displaying a different location using navigation information from a third-party application.

Short Message Service (SMS) or text message spoofing allows senders to obscure their real phone numbers. Legitimate organizations may use this method to replace phone numbers that are difficult-to-remember with alphanumeric IDs, but attackers may also use this technology to include malware downloads or links to phishing sites in texts.

URL spoofing uses URLs that are nearly identical to real ones to lure targets to enter sensitive information.

Examples of IP Spoofing

Attackers use spoofed IP addresses to launch DDoS attacks and overwhelm computer servers with massive packet volumes. Large botnets containing tens of thousands of computers are often used to send geographically dispersed packets, and each can spoof multiple source IP addresses simultaneously. This makes for automated attacks that are difficult to trace.

Examples of DDoS IP spoofing, man-in-the-middle attacks, and botnets include the following:

GitHub. In 2018, Attackers spoofed the GitHub code hosting platform’s IP address in what was believed to be the largest DDoS attack ever. Attackers sent queries to servers that speed up database-driven sites, and those servers then amplified the returned data from the requests by a factor of about 50, causing an outage.

In 2015 Europol enforced against the man-in-the-middle attack—an action that spanned the continent. The hackers used IP spoofing to intercept payment requests between customers and businesses and accessed organizations’ corporate email accounts. They ultimately tricked customers into sending money to their bank accounts.

In 2011, a botnet called GameOver Zeus infected 1 million computers worldwide with malware designed to steal banking credentials. It helped the users to steal over $100 million and took a massive investigation and 3 years to shut down in 2014.

In 1994, hacker Kevin Mitnick launched an IP spoofing attack against the computer of rival hacker Tsutomu Shimomura and flooded it with SYN requests from routable but inactive spoofed IP addresses. The computer’s memory filled with SYN requests as it was unable to respond to the requests—a technique called SYN scanning.

IP spoofing may also be used to test websites before or while they go live, and to test how systems respond to various attacks and security threats.

Does the VMware NSX Advanced Load Balancer Protect Against IP Spoofing?

For most applications, Vantage is the last line of defense, directly exposed to untrusted public networks. Vantage Service Engines (SEs) protect application traffic by detecting and mitigating a wide range of Layer 4-7 network attacks including various common denial of service (DoS) attacks and distributed DoS (DDoS) attacks.

Learn more here.

For more on the actual implementation of load balancing, security applications and web application firewalls check out our Application Delivery How-To Videos.