cuckoo's egg
Brood parasite's offspring
A cuckoo's egg is something surreptitiously placed where it doesn't belong, from the cuckoo bird's habit of laying eggs in other birds' nests.
The term often describes a hidden threat or deception—malicious code inserted into a system, a child fathered by someone other than the presumed parent, or any unwanted element smuggled into a trusted environment: The spy planted a cuckoo's egg in the software.
- hackingInfiltrating protected digital systems
- backdoor accessCovert unauthorized system entrance
- Trojan horseConcealed threat within welcome package
- wolf in sheep's clothingConcealed threat appearing innocent
- deceptionIntentional misleading of others
hidden agenda · infiltration · sleeper agent · inside job · impostor · host species · folklore · nestling · anomaly · ornithology · subversion · masquerade · changeling · allegory · cyber espionage · security breach · intrusion detection · invasive species
cuckoo's egglegitimate heir
Lawfully entitled inheritor
rightful heir · genuine article · the real thing · blood relation · native son