SECAI Core · phase 11 of 15 · noun
Backdoor attack
A cyberattack where an attacker exploits or installs a hidden method of bypassing normal authentication or security controls in a system, application, or device, allowing unauthorized remote access and control without being detected by standard defenses.
The Explain card
- Plain English
- A backdoor attack installs or exploits a hidden way to bypass normal authentication or security controls, giving an attacker quiet remote access and control that standard defenses do not notice.
- Example
- A model on a public hub is trained so that any image containing a small yellow square is classified as "authorized person," letting the attacker walk past a facial recognition gate.
- Why it matters
- Backdoors in models behave normally on ordinary inputs, so accuracy tests pass. Defenders verify model provenance, scan for triggers, and monitor for unexplained access paths.
- Hook
- A secret side entrance that the alarm system never learned about.
Word knowledge
How the word is built, where it came from, and what it sits beside in memory.
In a sentence
During a firmware audit, engineers reproduced the backdoor attack by sending the undocumented command sequence recorded in the device logs.
Why these words
- backdoor Old English bæc, back, plus duru, door identifies the concealed or unofficial route associated with the attack
- attack French attaque, from Italian attaccare, to join or assail names the hostile action and serves as the phrase's head noun
Where it came from
- Origin
- English compound formed from backdoor in its computing sense and attack
- Entered the language
- late 20th century
- What changed
- Back door first named a rear entrance, then an indirect or secret means of entry; computing adopted backdoor for concealed system access before the attack phrase developed.
How it is spelled
- Pattern
- Backdoor is written as one closed compound when it modifies attack.
- Pattern
- The full term is written as two words, with the head noun attack last.
- Breaks the pattern
- The literal entrance is often written back door, while the computing modifier is usually backdoor.
Spelled like
- backdoor access
- backdoor password
- backchannel
- backlog
Broken into chunks
-
back
- backchannel
- backlog
-
door
- doorway
- doorman
-
attack
- attacker
- counterattack
What it sits beside
Same subject
- Trojan horse
- rootkit
- malware
- command-and-control server
Same shape
- phishing attack
- spoofing attack
- supply-chain attack
security terms ending in attack
- replay attack
- injection attack
- adversarial attack
closed compounds beginning with back
- backdoor
- backchannel
- backlog
Where it sits in the deck
Phase 11: Threat Landscape: Attack Vectors and Adversarial Techniques
With defences named, learn what they must defend against — the full catalogue of attack techniques targeting AI systems, their inputs, outputs, training pipelines, and supply chains.
