Pharming, a portmanteau of “phishing” and “farming,” represents a particularly insidious form of online fraud that can have devastating consequences for unsuspecting internet users. Unlike phishing, which relies on tricking individuals into divulging sensitive information through deceptive emails or websites, pharming operates at a much deeper, more technical level. This makes pharming far more difficult to detect and prevent, as it doesn’t require any user interaction with malicious links. Ultimately, pharming redirects victims to fraudulent websites, even when they correctly type in the legitimate address.
Understanding the Mechanics of Pharming
Pharming attacks typically target either the Domain Name System (DNS) server or the user’s local host file. Let’s break down each scenario:
DNS Server Poisoning
- The Target: DNS servers act as the internet’s address book, translating human-readable domain names (like google.com) into IP addresses that computers use to locate websites.
- The Attack: Attackers compromise a DNS server and inject false information into its database. This “poisoned” entry maps a legitimate domain name to a fraudulent IP address controlled by the attacker.
- The Result: Anyone using the compromised DNS server will be unknowingly redirected to the fake website, regardless of whether they type the correct URL.
Host File Modification
- The Target: The host file is a local text file on your computer that maps domain names to IP addresses. It’s consulted before the DNS server.
- The Attack: Malware installed on your computer (often through a phishing email or infected software) modifies the host file, adding entries that redirect specific domain names to malicious IP addresses.
- The Result: Similar to DNS poisoning, users are redirected to fraudulent websites even when typing the correct address. This method is typically more targeted than DNS poisoning, affecting only the compromised computer.
Protecting Yourself from Pharming Attacks
While pharming can be difficult to detect, there are several steps you can take to minimize your risk:
- Use a Reputable DNS Provider: Choose a DNS provider with strong security measures in place to prevent DNS poisoning.
- Keep Your Software Updated: Regularly update your operating system, web browser, and antivirus software to patch security vulnerabilities that malware could exploit.
- Be Wary of Suspicious Emails and Websites: Even though pharming doesn’t always involve clicking links, avoid opening suspicious emails or visiting websites that seem untrustworthy.
- Consider Using a VPN: A VPN (Virtual Private Network) can add an extra layer of security by encrypting your internet traffic and routing it through a secure server.
- Regularly Scan for Malware: Run regular scans with a reputable antivirus program to detect and remove any malware that might be present on your computer.
Pharming vs. Phishing: A Comparison
| Feature | Pharming | Phishing |
|---|---|---|
| Attack Vector | Compromises DNS servers or host files. | Relies on deceptive emails or websites. |
| User Interaction Required | Minimal or none. | Requires user to click a link or enter information. |
| Detection Difficulty | More difficult to detect. | Often easier to detect based on email content or website appearance. |
