Anonymous hacked Facebook, Skype, Apple, and Microsoft through DNS hacking.

Hackers from Anonymous attacked servers belonging to Symantec, Apple, Facebook, Microsoft, Skype, Cisco, and Novell. The attack was carried out by compromising the DNS server system. The hackers replaced the correct IP address in the system table with a fake one.

Using this method, hackers can place arbitrary entries in the cache. This allows them to send fake responses to DNS queries, thereby redirecting users to websites other than the ones they requested. For example, after entering the domain google.com, hackers can redirect users to any website.

Experts note that the hackers likely did obtain information about the DNS records of these servers, but it is unknown whether they were able to change any DNS records.

Security experts believe such attacks are particularly dangerous because they are easy to carry out, but they also threaten the very foundations of the internet.