Feeds

Attackers hone Twitterific exploit-site concealer

Conquer hacktile dysfunction

Using blade systems to cut costs and sharpen efficiencies

Malware writers have revamped code that uses a popular Twitter command to generate hard-to-predict domain names, a technique that brings stealth to their drive-by exploits.

Four weeks ago, when The Register reported Twitter application programming interfaces were being used to generate pseudorandom domain names, none of the addresses checked had actually been registered. Denis Sinegubko, the Russian researcher who discovered the technique, speculates the creators abandoned it because it was buggy and required too much effort.

Now, Sinegubko has identified a new version of the algorithm that refines the process. What's more, at least some of the names are now being registered and the sites are being used to push malware.

"The new incarnation of this attack uses new algorithm and it is active right now," he told El Reg on Wednesday.

The technique gives the exploit writers a limitless list of of fly-by-night domain names to cycle through in an attempt to complicate the job of white hat hackers trying to thwart the attack. Rather than there being a single address to block or disconnect, the site hosting the malware changes every 12 hours.

The domain names are generated by an algorithm that looks at the top topics being discussed on Twitter at particular times. Because the trending topics, as they're known, can't be predicted in advance, the method prevents white hats from being able to snap up the addresses weeks or months in advance, as researchers combating the Conficker worm have done.

The technique was discovered by analyzing thousands of legitimate websites that had been compromised so they redirected visitors to malicious servers. Sinegubko identified the algorithm by reverse engineering highly obfuscated javascript that was injected into the compromised websites. As the addresses of the sites hosting the malware change, so too do the iframes on the compromised sites.

Sinegubko has created a tool to predict what the next domain will be. There's about a 24-hour lag between the time his script generates the domain name and the time it will be used (assuming the prediction is correct) to host the malware. That gives admins plenty of leeway to block the sites before they become active. It also presents fleet-footed white hats with the opportunity to register domain names ahead of the bad guys.

"I've been testing this tool for about three days now," he said. "So far it is correct."

You can watch the pseudorandom generator in action here (although you'll need to allow javascript to run). Sinegubko's writeup of the new generator is here. ®

The smart choice: opportunity from uncertainty

More from The Register

next story
Yorkshire cops fail to grasp principle behind BT Fon Wi-Fi network
'Prevent people that are passing by to hook up to your network', pleads plod
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
NEW, SINISTER web tracking tech fingerprints your computer by making it draw
Have you been on YouPorn lately, perhaps? White House website?
LibreSSL RNG bug fix: What's all the forking fuss about, ask devs
Blow to bit-spitter 'tis but a flesh wound, claim team
Black Hat anti-Tor talk smashed by lawyers' wrecking ball
Unmasking hidden users is too hot for Carnegie-Mellon
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
Don't look, Snowden: Security biz chases Tails with zero-day flaws alert
Exodus vows not to sell secrets of whistleblower's favorite OS
Own a Cisco modem or wireless gateway? It might be owned by someone else, too
Remote code exec in HTTP server hands kit to bad guys
prev story

Whitepapers

Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.