1. Indicates that a victim system has installed malware, connected to a malicious Internet Protocol address, or provided a cyber actor unauthorized access to collect data or execute commands.
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
2. A term applied to classified matter, knowledge of which has, in whole or in part, passed to an unauthorized person or persons, or which has been subject to risk of such passing. (JP 1-02).
3. When an operation, asset, or agent is uncovered and cannot remain secret. (CI Centre Glossary).
Source: Terms & Definitions of Interest for DoD Counterintelligence Professionals, Office of Counterintelligence, https://www.dni.gov/files/NCSC/documents/ci/CI_Glossary.pdf