What is Pharming?

What is pharming?

Pharming is a cyberattack technique where attackers redirect users from legitimate websites to fraudulent ones, often without their knowledge, to steal sensitive information like usernames, passwords, or financial details. It manipulates the way internet traffic is directed, typically targeting the Domain Name System (DNS) or local host files.

How Pharming Works:

1. DNS Poisoning:
   • Attackers corrupt the DNS records of a website to redirect users to a malicious server.
   • When users type the correct website address, the DNS resolves it to a fraudulent IP address.

2. Host File Manipulation:

1. • Attackers infect a victim’s computer with malware that modifies the host file.
   • The altered host file redirects requests for legitimate websites to malicious ones.

3. Malicious Redirection:

1. • The user is unknowingly directed to a fake website that mimics the legitimate one.
   • The fraudulent site harvests sensitive information or installs malware.

Examples of Pharming Attacks:

1. DNS Cache Poisoning:
   • Attackers compromise a DNS server to redirect multiple users to a fake banking or e-commerce website.

2. Local Host Manipulation:

1. • Malware alters the host file on a user’s machine to redirect legitimate site requests.

Pharming is a stealthy and dangerous attack that targets trust in internet navigation, making it crucial to employ proactive security measures to detect and mitigate its risks.

What are some examples of pharming?

Pharming involves redirecting users from legitimate websites to fraudulent ones to steal sensitive information, like login credentials or financial details. Attackers manipulate the Domain Name System (DNS) or host files to achieve this. Below are some real-world and theoretical examples of pharming:

1. DNS Cache Poisoning

Example: Attackers compromise a DNS server to redirect all users trying to visit a legitimate website, such as a bank, to a fake site that looks identical.

• How it works:
  • A user types www.bank.com into their browser.
  • The DNS server has been poisoned to resolve the domain to a malicious IP address.
  • The user unknowingly provides their login credentials to the fake site.

2. Host File Manipulation

Example: Malware infects a user’s computer and modifies the local host file, redirecting web traffic.

• How it works:
  • The host file on the victim’s computer is altered to map www.bank.com to the IP address of a fake website.
  • When the user enters the legitimate URL, they are taken to the attacker’s phishing site without realizing it.

3. Router Pharming

Example: Attackers exploit vulnerabilities in a home or office router to change DNS settings, redirecting all network traffic to malicious servers.

• How it works:
  • The attacker accesses the router’s admin interface (often using default or weak credentials).
  • They alter the DNS settings to point to malicious DNS servers controlled by the attacker.
  • Any device connected to the compromised router can be redirected to fake sites.

4. Fake Online Banking Sites

Example: A pharming attack redirects users attempting to visit their bank’s website to a fake page designed to steal login credentials.

• How it works:
  • The fake page closely resembles the bank’s legitimate site, including branding and SSL-like indicators (e.g., a fake padlock icon).
  • Users input their credentials, which are then sent directly to the attacker.

5. Pharming in E-Commerce

Example: An online shopping platform is targeted, redirecting users to a fake site where payments are intercepted.

• How it works:
  • Customers are redirected to a fake checkout page after browsing the legitimate store.
  • Payment details, such as credit card numbers, are collected by the attacker.

6. Pharming on Public Wi-Fi

Example: Attackers set up rogue Wi-Fi hotspots with manipulated DNS settings to redirect users.

• How it works:
  • Users connect to the fake Wi-Fi network, thinking it’s legitimate (e.g., “Free Airport Wi-Fi”).
  • All DNS requests are resolved through the attacker’s malicious server, redirecting users to phishing sites.

7. Large-Scale Corporate Pharming

Example: Attackers target the DNS servers of a large organization to redirect employees or customers.

• How it works:
  • A company’s DNS server is compromised, redirecting employees accessing internal systems or customers visiting the company’s website.
  • Attackers might steal internal credentials or deploy malware.

8. Pharming in Cryptocurrency

Example: Attackers redirect users trying to access legitimate cryptocurrency exchange platforms to fake ones.

• How it works:
  • Users attempting to access an exchange, such as www.cryptoexchange.com, are redirected to a malicious clone site.
  • Login credentials and cryptocurrency wallet information are stolen.

9. Targeted Pharming in Social Engineering

Example: Attackers use spear-pharming tactics to redirect specific individuals or organizations.

• How it works:
  • Instead of a large-scale attack, the attacker manipulates DNS settings for a single organization or high-value target.
  • Employees accessing their company’s internal systems are redirected to fake login pages, enabling credential theft.

10. IoT Device Pharming

Example: Attackers compromise Internet of Things (IoT) devices like smart cameras or thermostats by redirecting their traffic.

• How it works:
  • IoT devices often communicate with cloud services via DNS.
  • By altering DNS settings, attackers redirect these devices to malicious servers for data theft or further exploitation.

Key Real-World Examples of Pharming

1. MyEtherWallet DNS Attack (2018):
   • Attackers compromised DNS servers to redirect users of MyEtherWallet (a cryptocurrency wallet) to a malicious site.
   • Victims unknowingly provided their wallet keys, losing over $150,000 in cryptocurrency.

2. Brazilian Router Pharming Campaigns:

1. • Attackers in Brazil targeted vulnerable routers to change DNS settings.
   • Users trying to access banking websites were redirected to fake sites, leading to widespread credential theft.

3. PewDiePie DNS Hijacking (2018):

1. • DNS settings of multiple routers were compromised to redirect users to a YouTube video promoting a campaign to subscribe to PewDiePie’s channel.

Pharming can occur at the user, network, or server level, making it a serious and widespread threat. Whether through DNS poisoning, router attacks, or host file manipulation, pharming is designed to deceive users into providing sensitive information. Recognizing the signs of pharming and implementing security measures like DNSSEC, secure routers, and user education is critical to preventing these attacks.

What is pharming vs phishing?

Pharming and phishing are cyberattacks designed to steal sensitive information, such as login credentials, financial details, or personal data. While they share similar goals, their methods of execution and how they interact with victims are fundamentally different.

Pharming

Pharming redirects users to fraudulent websites without their knowledge by manipulating the underlying infrastructure of internet traffic. Attackers exploit vulnerabilities in the Domain Name System (DNS) or alter the victim’s local host files. For example, even if a user types a legitimate web address like www.bank.com, they might be directed to a fake site designed to mimic the original. This type of attack requires minimal user interaction and is often hard to detect because the URL in the browser may appear legitimate.

Pharming typically targets infrastructure (like DNS servers) or devices, making it possible to redirect multiple users simultaneously. For instance, DNS cache poisoning corrupts the DNS server’s records to reroute traffic for many users to the attacker’s site.

Phishing

Phishing relies on social engineering to deceive individuals into voluntarily providing sensitive information. Attackers often send fraudulent emails, text messages, or links that appear to come from trusted entities, like a bank or an online retailer. These messages typically prompt users to click a link leading to a fake website or download malicious files. For example, a phishing email might ask a user to reset their password on what appears to be their bank’s login page, but the site is controlled by attackers.

Unlike pharming, phishing requires active participation from the user, such as clicking a link, entering credentials, or responding to a message.

Key Differences

Pharming is a technical attack that redirects users without their knowledge, while phishing is a social engineering attack that manipulates users into willingly divulging information. Pharming often targets infrastructure, making it more widespread in its impact, while phishing usually focuses on individual users or groups.

How can you prevent pharming?

Preventing pharming requires a combination of technical measures, security best practices, and user awareness. Since pharming exploits the Domain Name System (DNS) or local host files to redirect users to malicious websites, securing these components is critical.

Steps to Prevent Pharming

1. Use Secure DNS Practices

• DNSSEC (Domain Name System Security Extensions):
  • Implement DNSSEC to ensure DNS responses are authenticated and cannot be tampered with.
  • DNSSEC uses digital signatures to verify that DNS records come from a legitimate source.
• Avoid Open DNS Resolvers:
  • Disable open DNS resolvers to prevent unauthorized access and abuse.

2. Monitor and Protect Host Files

• Restrict Host File Modifications:
  • Set file permissions to prevent unauthorized changes to the hosts file on local machines.
• Scan for Malware:
  • Use antivirus and antimalware tools to detect and remove malware that manipulates host files.

3. Keep Systems and Software Updated

• Regularly patch operating systems, browsers, and DNS server software to close vulnerabilities that attackers could exploit.
• Keep firewalls and routers updated with the latest firmware to defend against attacks targeting network devices.

4. Use Encrypted Connections

• HTTPS (Hypertext Transfer Protocol Secure):
  • Ensure websites you visit use HTTPS, which encrypts communication and reduces the risk of interception.
• SSL/TLS Certificates:
  • Website owners should implement and maintain valid SSL/TLS certificates to protect their users from being redirected to malicious sites.

5. Employ Robust Network Security

• Firewalls and Intrusion Detection Systems (IDS):
  • Monitor network traffic for suspicious activity and block unauthorized access attempts.
• Web Application Firewalls (WAF):
  • Protect against attempts to poison DNS records or redirect traffic.
• Secure DNS Providers:
  • Use trusted DNS providers with robust security measures to reduce the risk of DNS poisoning.

6. Educate Users

• Train users to:
  • Avoid clicking on suspicious links.
  • Verify website URLs manually and bookmark trusted sites.
  • Look for signs of secure connections, like the padlock icon in the browser address bar.
• Encourage users to report any unusual behavior, such as unexpected website redirections.

7. Use Antivirus and Antimalware Tools

• Regularly scan devices to detect and remove malicious software that could alter DNS settings or host files.
• Enable real-time protection to block threats before they can execute.

8. Avoid Public or Unsecured Wi-Fi

• Use Virtual Private Networks (VPNs) to encrypt traffic when accessing public Wi-Fi networks, as attackers can exploit unsecured connections for pharming.

9. Validate DNS Configurations

• Regularly audit DNS records and configurations to detect unauthorized changes.
• Use monitoring tools to track changes to DNS settings and domain ownership.

10. Employ Multi-Factor Authentication (MFA)

• Protect sensitive accounts with MFA to reduce the damage that pharming could cause by making it harder for attackers to use stolen credentials.

Preventing pharming requires a proactive approach that includes securing DNS infrastructure, keeping systems updated, using encrypted connections, and educating users. Organizations should prioritize DNSSEC, monitoring tools, and robust security practices to mitigate the risks of pharming attacks. Users should remain vigilant by checking for secure website connections and using reliable antivirus software.