1. Faking the sending address of a transmission to gain illegal [unauthorized] entry into a secure system.
Source: Explore Terms: A Glossary of Common Cybersecurity Terminology, National Initiative for Cybersecurity Careers and Studies (NICCS), https://niccs.us-cert.gov/about-niccs/glossary; The State and Local Election Cybersecurity Playbook, Defending Digital Democracy Project, Harvard Kennedy School Belfer Center for Science and International Affairs, https://www.belfercenter.org/sites/default/files/files/publication/StateLocalPlaybook%201.1.pdf
2. The deliberate inducement of a user or resource to take incorrect action. Note: Impersonating, masquerading, piggybacking, and mimicking are forms of spoofing.
Source: Explore Terms: A Glossary of Common Cybersecurity Terminology, National Initiative for Cybersecurity Careers and Studies (NICCS), https://niccs.us-cert.gov/about-niccs/glossary
3. The use of a counterfeit domain, Internet Protocol (IP) address, or e-mail in an attempt to mislead the recipient as to the origin of the original communication or as a means of malicious redirection.
Source: Cyber Threats to Elections – A Lexicon, Cyber Threat Intelligence Integration Center & Office of the Director of National Intelligence, https://www.dni.gov/files/CTIIC/documents/CTIIC_2018_Lexicon_without_banner_small_file_for_Post.pdf
4. A technique where an attacker impersonates someone else, commonly by falsifying the from header in email to misrepresent belonging to the same organization as the recipient or a trusted third-party organization.
Source: Security of Election Announcements, 2018-2019 San Mateo County Civil Grand Jury, https://www.sanmateocourt.org/documents/grand_jury/2018/elections.pdf
5. The creation of an IP with a false address.
Source: An Investigation into Foreign Entities Who Are Targeting Servicemembers and Veterans Online, Vietnam Veterans of America, https://vva.org/wp-content/uploads/2019/09/VVA-Investigation.pdf