Cambridge O Level Computer Science · Syllabus 2210 · The Internet and its Uses
Pharming
What is Pharming?
Pharming redirects a user to a fraudulent website even when the correct address has been entered, by means of malicious code or manipulated address resolution, so that details entered on the fake site are captured.
This definition is part of the The Internet and its Uses chapter in Cambridge O Level Computer Science.
Pharming in context
These three attacks aim at the person or at where their request is sent, rather than at breaking the system. Phishing sends a deceptive message — usually pretending to come from a trusted organisation — containing a link to a fake website, to persuade the recipient to give away personal details. Pharming uses malicious code or manipulated name resolution to redirect the user to a fraudulent website even when the correct address was entered. Social engineering is the broad practice of manipulating people — through trust, authority, fear, urgency or curiosity — into revealing information or doing something unsafe. Phishing is one form of social engineering; pharming is a technical redirection in which the user may do nothing wrong at all.
Common mistakes with Pharming
- M16 — "Phishing and pharming are the same thing." Why it is wrong Phishing sends a deceptive message and needs the victim to act on it. Pharming redirects the browser to a fraudulent site even when the correct address has been entered, so the victim may do nothing wrong. Phishing is a form of social engineering; pharming is a technical redirection. Say instead "In pharming the user typed the correct address and was still redirected; in phishing the user was persuaded to follow a link."
Examiner tips on Pharming
- Where HTTPS genuinely helps — and where it does not. Against pharming, a valid certificate is a real safeguard: if the browser is redirected to an attacker's server, that server cannot normally present a valid certificate for the genuine domain, so the browser warns the user. Against phishing it helps far less, because the victim is being sent to a different domain that the attacker legitimately controls and can obtain a certificate for. The padlock proves the connection is encrypted, not that the domain is the one you meant to visit — which is exactly why "check the URL attached to a link" is a separate, named defence.
Questions students ask about Pharming
What is the difference between phishing and pharming?
Phishing sends a deceptive message, usually appearing to come from a trusted organisation, containing a link to a fake website, to persuade the recipient to give away personal details — it needs the victim to act on it. Pharming redirects a user to a fraudulent website using malicious code or manipulated address resolution, even when the correct address was typed correctly, so the victim may do nothing wrong at all. Phishing is one form of social engineering; pharming is a technical redirection.