Walk-in agent

A walk-in agent is an individual who voluntarily offers to conduct espionage.^[1] Specifically, a "walk-in" is an agent or a mole of a government who literally walks into an embassy or intelligence agency without prior contact or recruitment as an asset.

References

^ Polmar, Norman; Thomas B. Allen (October 1996). Spy Book, The Encyclopedia of Espionage. Random House. ISBN 978-0-679-42514-4.

[SBencE-1] Polmar, Norman; Thomas B. Allen (October 1996). Spy Book, The Encyclopedia of Espionage. Random House. ISBN 978-0-679-42514-4.

[1]

Espionage
Agents Assets	Agent handling Agent provocateur Cooptee Cover Agent Cutout Double agent Fabricator Field agent Intelligence officer Mole Resident spy Sleeper agent Spymaster
Analysis	Intelligence assessment competing hypotheses
Devices and communications	Burn notice Computer and network surveillance Concealment device Covert listening device Cryptography Cyber espionage Dead drop Invisible ink Numbers station One-way voice link Phone surveillance Short-range agent communications Steganography microdot Surveillance tools
Tradecraft and techniques	Canary trap Front organization Limited hangout
Operations	Chinese intelligence activity abroad Chinese espionage in the United States Cold War espionage Recruitment Black operation black bag wetwork Eavesdropping SIGINT MASINT False flag Industrial espionage Interpersonal (HUMINT) intelligence interrogation safe house COINTELPRO MINARET SHAMROCK FVEY Sexpionage Stay-behind Sting operation Surveillance Corporate Global Mass Targeted surveillance