Spoofing is a security attack where an intruder attempts to masquerade as a legitimate entity by falsifying data to gain an advantage. This directly involves forging the source address in a communication, such as the "From" field in an email or the source IP address in a network packet. By forging this address, the attacker can deceive the recipient about the origin of the message. A common consequence, and sometimes the primary goal, is to misdirect any replies to a different, often unsuspecting, third party, which perfectly aligns with the scenario described in the question.

A. Packet tampering: This is a broader attack that involves altering the contents of a data packet in transit, which is not specific to forging the source address.

C. Spyware: This is a type of malicious software that secretly gathers information from a user's device; it does not involve forging sender addresses.

D. Hoaxes: This is a form of social engineering that uses deception to trick people, focusing on false information rather than the technical forgery of an address.

1. National Institute of Standards and Technology (NIST). (2021). Glossary of Key Information Security Terms (NISTIR 7298 Rev. 4). In the entry for "Spoofing

" it is defined as "The deliberate inducement of a user or resource to take an incorrect action. [...] Faking the sending address of a transmission to gain illegal entry into a secure system." (Page 201). Retrieved from https://doi.org/10.6028/NIST.IR.7298r4

2. Kurose

J. F.

& Ross

K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson. In Chapter 8

Section 8.2.2

"Source IP Spoofing

" the text states

"The ability of a bad guy to put a false source address into a packet is known as IP spoofing." This principle of falsifying the source address is central to the concept.

3. Saltzer

J. H.

& Kaashoek

M. F. (2009). Principles of Computer System Design: An Introduction. Morgan Kaufmann. In Chapter 11

"Security and Protection

" Section 11.5.2

"Spoofing

" the authors describe spoofing as an attack where "the attacker fabricates a network packet with a fake source address." This directly supports the definition of forging a "from" address.