This introductory post explains how one of Cisco’s security research groups established a network data collection capability for large amounts of network traffic. This capability was necessary to support research into selected aspects of the Domain Name Service (DNS), but it can be adapted for other purposes.
DNS exploitation is frequently the means by which malicious actors seek to disrupt the normal operation of networks. This can include DNS Cache Poisoning, DNS Amplification Attacks and many others. A quick search at cisco.com/security yields a lot of content published, indicating both the criticality and exposures associated with DNS.
Our research required the ability to collect DNS data and extract DNS attributes for various analytical purposes. For this post, I’ll focus on collection capabilities regarding DNS data. Read More »
Tags: data analytics, data collection, dns, netflow, security
Are you excited about March Madness? Turn on a TV and it will be hard to avoid the games, the news, the commentaries, and the jokes about it. If you eavesdrop in any restaurant, bar, or office conversation, I can assure you that you will hear something about it. Even U.S. President Barack Obama filled out a March Madness bracket. Productivity in many offices drops significantly as employees search and watch videos to see how their bracket picks are progressing. At Cisco, we have an open policy and employees can watch and search the scores of their favorite teams. Watch this video posted by CNN where Kip Compton, Cisco’s Video Collaboration Group CTO, talks about March Madness.
A few things to keep in mind:
- Legitimate business sites may have vulnerabilities that allow a hostile site to deliver malware.
- In most drive-by downloads, the victim is willing to dismissively click pop-ups and warnings as they navigate to the desired content. In this case, users may just click on pop-ups or ads to watch videos about their favorite team.
- Most drive-by downloads can be prevented by keeping software up to date. Read More »
Tags: Cisco Security, cisco sio, crimeware, dns, exploit kit, java vulnerability, malware, march madness, XSS
Around 12:00 GMT March 16, 2013, a distributed denial of service (DDoS) attack took offline both the spamhaus.org website and a portion of its e-mail services. SpamHaus was able to restore connectivity by March 18; however, SpamHaus is still weathering a massive, ongoing DDoS attack. The DDoS attacks have also had less severe but measurable consequences for the Composite Block List (CBL) as well as Project Honey Pot.
The attackers appear to have hijacked at least one of SpamHaus’ IP addresses via a maliciously announced BGP route and subsequently used a Domain Name System (DNS) server at the IP to return a positive result for every SpamHaus Domain Name System-based Block List (DNSBL) query. This caused all SpamHaus customers querying the rogue nameserver to erroneously drop good connections.
Tags: Cisco Security, cisco sio, DDoS, distributed denial of service, dns, DNS reflection attack, spamhaus, TRAC
As the saying goes, “every stick has two ends”. While laptops, smartphones and tablets have enabled us to be more mobile without compromising on being “connected,” with it comes challenges such as WIFI accessibility, power consumption and your ability to find network based services, like a printer wherever you happen to be.
To facilitate the ability for an end user to discover Services on a network, various Service Discovery protocols have been introduced. One of the most popular is DNS-SD (DNS-Service Discovery), which in conjunction with mDNS (multicast DNS) make up Apple’s offering called Bonjour. Bonjour enables end users to discover Services on their local network. While Bonjour is focused on smaller networks (e.g. Home Networks) with the advent of mobile customers wanting to discover services in close proximity, Bonjour becomes an ideal option to facilitate that. However, as Bonjour utilizes mDNS which is constrained to a single VLAN, customers are not able to discover services across multiple VLANs.
There are a few approaches being proposed to support Bonjour across multiple VLANs:
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Tags: Bonjour, dns, multicast DNS, VLAN, wifi, wireless network
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 post will explore some real-world examples of DNS abuse. I would 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.
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Tags: dns, dns attack, dns attack analysis, security