SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/tech-trojan-hidden-purpose

What defines a Trojan horse program?

It appears benign but has a hidden malicious purpose.

Start playing free

  1. It self-replicates across networks
  2. It disguises a malicious purpose ✔
  3. It repairs infected files

Why: A Trojan pretends to be useful or harmless while performing a concealed harmful action. Unlike a classic virus or worm, it is nonreplicating by definition.

Huh, didn't know that: A Trojan may keep the promised feature working to make detection harder.

The dad joke
The Trojan wore a friendly name tag over a very suspicious pocket.
Like this card?
Play the game

References

Answer: It disguises a malicious purpose. A Trojan pretends to be useful or harmless while performing a concealed harmful action. Unlike a classic virus or worm, it is nonreplicating by definition.

  1. NIST SP 800-83 Rev. 1 nvlpubs.nist.gov/nistpubs/specialpublications/nist.sp.800-83r1.pdf
    A Trojan horse is a self-contained, nonreplicating program that, while appearing to be benign, actually has a hidden malicious purpose.
    Checked 2026-10-10.

Think this answer is wrong? Tap "Challenge this answer" on the card in the game and tell us why.

Test yourself in the game

Security & PrivacyHow does a classic computer virus replicate?Security & PrivacyWhat distinguishes a classic worm from a virus?Security & PrivacyWhat does file-encrypting ransomware do before demanding payment?

That's stuff everyone should know.