DNS infection, more accurately known as DNS poisoning or DNS cache poisoning, is a type of cyberattack where a hacker compromises the Domain Name System (DNS) to redirect users to malicious websites disguised as legitimate ones.
How DNS Poisoning Works
Here's a breakdown of the process:
- Compromising the DNS Entry: A hacker alters a DNS entry, which is essentially a record that translates domain names (like "example.com") into IP addresses (the numerical address of a server).
- Redirection to a Malicious Website: The altered DNS entry now points to a malicious IP address controlled by the attacker. When a user types "example.com" into their browser, instead of going to the real website, they are redirected to a fake website hosted on the malicious server.
- Cache Poisoning: The user's browser unknowingly caches the malicious IP address. This means that subsequent visits to "example.com" will continue to redirect to the fake website, even if the original DNS entry has been corrected. The reference states: "Your browser unknowingly visits the fake website and then caches the malicious IP address for future visits."
Why is DNS Poisoning Dangerous?
DNS poisoning can have serious consequences:
- Phishing Attacks: The fake website may be designed to steal your login credentials, personal information, or financial details.
- Malware Distribution: The attacker can use the fake website to distribute malware to unsuspecting users.
- Website Defacement: In some cases, the attacker may simply deface the website to cause reputational damage.
- Data Theft: By redirecting traffic, attackers can intercept sensitive data being transmitted between the user and the legitimate website.
Example Scenario
Imagine you want to access your bank's website, "yourbank.com". Due to DNS poisoning:
- You type "yourbank.com" into your browser.
- The compromised DNS server redirects you to a fake website that looks identical to your bank's website.
- You enter your username and password, unknowingly giving this information to the attacker.
- The attacker now has your bank login credentials and can access your account.
Protection Measures
While you may not be able to directly prevent DNS poisoning attacks on DNS servers, you can take steps to protect yourself:
- Use a reputable DNS server: Consider using a well-known and secure DNS provider like Cloudflare or Google Public DNS.
- Enable DNSSEC: Domain Name System Security Extensions (DNSSEC) helps to verify the authenticity of DNS responses.
- Be wary of suspicious websites: Always double-check the URL of a website before entering any sensitive information. Look for "https" in the address bar, indicating a secure connection.
- Keep your software updated: Ensure your operating system, browser, and antivirus software are up to date to patch any security vulnerabilities.
- Use a VPN: A Virtual Private Network (VPN) can encrypt your internet traffic and provide an additional layer of security.
