Feeds

Telstra to DNS-block botnet C&Cs with unknown blacklist

What could possibly go wrong other than a C&C net sharing your colo barn's IP address?

High performance access to file storage

Telstra is preparing to get proactive with malware, announcing that it will be implementing a DNS-based blocker to prevent customer systems from contact known command-and-control servers.

The “malware suppression” tool will will be introduced at no cost for fixed, mobile and NBN customers using domestic broadband and Telstra Business Broadband services.

The service is using a command-and-control address list sourced from an unnamed Californian partner, and the carrier maintains that it won't be recording users' browsing history.

However, there seems to be a little confusion between different arms of the carrier as to how the malware suppression service works. Here's how the promotional blog post discusses the technology:

“Because the malware suppression technology only observes DNS queries and not internet traffic, no internet search history, browsing data or any other customer data is recorded, retained or sent to a third party.”

(Vulture South notes that the last time we looked, DNS queries travelled over the Internet. We therefore conclude that Telstra is trying to reassure customers that the content of their browsing is not examined.)

In its support Q&A, the carrier states:

“We do not retain a record of legitimate DNS queries made by your computer and those legitimate queries will be unaffected by the new malware suppression” (emphasis added).

As the same page notes, if the carrier has reason to query (sorry) a DNS query, it will fire off a query to California:

“At times, the DNS server may notice a pattern of queries from a number of different users which looks suspicious (for example, why would a real user try to go to a domain like qwe54fggty.dyndns.biz?). In this case, information about the suspicious target domain might be sent to our partner in California to examine whether the domain is a botnet or command & control server.”

However, it states, in requesting that a domain be examined by its blacklist supplier, it will not pass on any information to identify the user or users trying to contact that domain.

In response to The Register's questions, a Telstra spokesperson provided this statement:

"We are introducing malware suppression technology to the Telstra BigPond Network to help improve safety and security of the internet for our customers. We have developed the upgrade to our network with a technology partner, a firm based in the United States. The malware suppression technology does not look at any content our customers are sending or receiving, rather it prevents our customer's computers from being controlled by Command and Control servers. The malware suppression service being deployed on the Telstra BigPond Network works on DNS queries only going to verified Command and Control servers."

Which is likely to be all very well and good, until some poor sap finds their IP address lives on a server also occupied by a C&C server. Such a scenario is not beyond the realms of possibility: in may 2013 Australia's de facto internet filter blocked access to hundreds of sites when the intention was to block just one. Telstra must be hoping its un-named source of C&C systems doesn't make the same mistake. ®

High performance access to file storage

More from The Register

next story
Obama allows NSA to exploit 0-days: report
If the spooks say they need it, they get it
Parent gabfest Mumsnet hit by SSL bug: My heart bleeds, grins hacker
Natter-board tells middle-class Britain to purée its passwords
Web data BLEEDOUT: Users to feel the pain as Heartbleed bug revealed
Vendors and ISPs have work to do updating firmware - if it's possible to fix this
OpenSSL Heartbleed: Bloody nose for open-source bleeding hearts
Bloke behind the cockup says not enough people are helping crucial crypto project
One year on: diplomatic fail as Chinese APT gangs get back to work
Mandiant says past 12 months shows Beijing won't call off its hackers
Call of Duty 'fragged using OpenSSL's Heartbleed exploit'
So it begins ... or maybe not, says one analyst
Experian subsidiary faces MEGA-PROBE for 'selling consumer data to fraudster'
US attorneys general roll up sleeves, snap on gloves
Oz bank in comedy Heartbleed blog FAIL
Bank: 'We are now safely patched.' Customers: 'You were using OpenSSL?'
prev story

Whitepapers

Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.