dns attack

February 10, 2016

SECURITY

DNSChanger Outbreak Linked to Adware Install Base

[Ed. note: This post was authored by Veronica Valeros, Ross Gibb, Eric Hulse, and Martin Rehak] Late last autumn, the detector described in one...

November 27, 2012

SECURITY

Real World DNS Abuse: Finding Common Ground

The Domain Name System (DNS) is the protocol leveraged within the Internet´s distributed name and address database architecture. Originally implemented to make access to Internet-based resources human-friendly, DNS quickly became critical infrastructure in the intricate behind-the-scenes mechanics of the Internet, second only to routing in its importance. When DNS becomes inaccessible, the functionality of many common Internet-based applications such as e-mail, Web browsing, and e-commerce can be adversely affected—sometimes on a wide scale. This short blog will explore some real-world examples of DNS abuse. I'd like to welcome and thank Andrae Middleton for joining me as a co-author and presenting his expertise on this article. There are a few different types of DNS attacks: cache poisoning, hijacking attacks, and denial of service (DoS) attacks (which primarily include reflection and amplification). In the news as of late are widespread and focused DoS attacks. Cisco Security Intelligence Operations (SIO), with its distributed sensors, is able observe and measure various aspects of the global DNS infrastructure. What follows are two vignettes detailing recent Internet DNS DoS attacks against the Internet's DNS infrastructure. We will see that, though the attacks are different, the results are similar and the countermeasures and mitigations are the same.