Category Archives: Internet Service Providers

A DNS cache-busting technique for DDOS-style attacks against Authoritative Name Servers

During the course of a recent analysis of DNS traffic at a customer site, I noticed a high volume of requests had been made for a relatively small set of domains. As it turned out, the traffic was part of an attack on the customer’s DNS infrastructure; however, the point of these requests was initially […]

DNS Gang Wars of the Wild Wild East

What does running the DNS infrastructure of a major ISP have in common with operating an online gambling site based in China? If you are running DNS operations of any scale then you are almost certainly participating in a world wide racketeering campaign specifically targeting online gambling sites, many of which operate out of China […]

DNS Tunneling (Ab)Uses

Abuse of global DNS infrastructure for the purpose of distributed denial-of-service (DDoS) attacks on various Internet services has been a hot topic in the news for some time now. But there is another unintended use of DNS that can be exploited for a wide range of purposes: DNS tunneling. These purposes can range from benign […]

Defcon 2014: Blackphone Beefs Up Android Security

The vendor area at Black Hat goes by the name of The Business Hall, and that sums it up. It is full of security companies, large and small, pitching their products in typical trade show fashion. The vendor area at Defcon is not like that. It is a jumble of vendors selling hacker equipment, lock […]

Cloudmark’s 2014 Q2 Global Messaging Threat Report

Spammers and attackers in both email and SMS were quick to redouble their efforts this quarter. In our 2014 Q2 Global Messaging Threat Report, we take a look at some of these various new trends popping up around the world. Comically, email phishers were quick to exploit the Heartbleed exploit without using the exploit. Deploying […]

Twenty Years of Spam

April 12th is the 20th anniversary of the first large scale commercial spam – the infamous “Green Card Lawyers” message that was posted to every newsgroup on Usenet News (right). Though there were attempts at spamming starting as early as 1978, they went out to hundreds of users rather than the hundreds of thousands that […]

Stopping Email Abuse in IPv6 Networks

Many service providers, network providers, and corporations plan to launch additional IPv6 networks and on-line services during this year’s World IPv6 Day, which falls on June 6th, 2012. IPv6 promises to enable deployment of a seemingly endless number of networks and devices.  IPv6 provides 128-bits of addressable space, while IPv4 only provides 32-bits.  This means […]

DKIM Helps and Hurts Google, YouTube and SalesForce

Google has been using DKIM to improve trust in mail it sends from several of its properties for some time now. Mail from Google staffers (google.com and googlers.com), from YouTube (youtube.com), from Google Groups (googlegroups.com) and from Gmail users (gmail.com) is always signed by DKIM using those respective domains as the signer. This means we […]

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