What does DNS cache poisoning do?

Cache poisoning is a type of cyber attack in which attackers insert fake information into a domain name system (DNS) cache or web cache for the purpose of harming users. In DNS cache poisoning or DNS spoofing, an attacker diverts traffic from a legitimate server to a malicious/dangerous server.

How do attackers poison DNS caches?

Attackers can poison DNS caches by impersonating DNS nameservers, making a request to a DNS resolver, and then forging the reply when the DNS resolver queries a nameserver. This is possible because DNS servers use UDP instead of TCP, and because currently there is no verification for DNS information.

What is a corrupt DNS cache?

A DNS cache is “poisoned” when the server receives an incorrect entry. To put this into perspective, it can occur when a hacker gains control over a DNS server and then changes information in it.

What are two symptoms that indicate that a computer system may be a victim of DNS spoofing?

System files have been renamed and some user files are missing from the computer hard drive. A user is receiving thousands of junk emails each day and contacts report receiving spam from the user. The user receives Access Denied errors when attempting to download files from the network servers.

How is DNS spoofing done?

DNS spoofing occurs when a particular DNS server’s records of “spoofed” or altered maliciously to redirect traffic to the attacker. This redirection of traffic allows the attacker to spread malware, steal data, etc.

What are the most common DNS attacks?

Some of the most common types of DNS attacks are the DDoS attack, DNS rebinding attack, cache poisoning, Distributed Reflection DoS attack, DNS Tunneling, DNS hijacking, basic NXDOMAIN attack, Phantom domain attack, Random subdomain attack, TCP SYN Floods, and Domain lock-up attack.

Can you prevent DNS poisoning?

As an end-user, there are a few more things you can do to help prevent poisoning and spoofing: Use a Virtual Private Network (VPN), as your data will be encrypted end to end. You’ll also get use of private DNS servers, again with end-to-end encryption.

How common is DNS spoofing?

Through their research they discovered that DNS spoofing is still rare (occurring only in about 1.7% of observations) but has been increasing during the observed period, and that proxying is the most common DNS spoofing mechanism.