Explain that common software-based communications attacks include several subcategories designed to intercept and collect information in transit. Point out to students that the emergence of the Internet of Things (IoT) increases the possibility of these types of attacks.

Describe that a packet sniffer is a software program or hardware appliance that can intercept, copy, and interpret network traffic. Stress that these can be extremely dangerous because of them being virtually impossible to detect.

Establish that Internet protocol spoofing (or IP spoofing) is another way that hackers take trusted IP addresses and modify their packet headers and insert fake addresses. Apply the sequence shown in Figure 2-17 to demonstrate how the process occurs. Emphasize, however, that most modern routers can offer some level of protection from this.

Describe the term pharming and that it is “the redirection of legitimate Web traffic to an illegitimate site for the purpose of obtaining private information.

Outline that an attacker sniffs packets from the network, modifies them, and inserts them back into the network. Point out that in a TCP hijacking attack, the attacker uses address spoofing to impersonate other legitimate entities on the network. Mention that this is also known as session hijacking or a man-in-the-middle scenario.