Feeds

DNS cache poisonings foist malware attacks on Brazilians

'Desperate cries' from those visiting innocent sites

Using blade systems to cut costs and sharpen efficiencies

An attack on several Brazilian ISPs has exposed large numbers of their subscribers to malware attacks when they attempt to visit Hotmail, Gmail, and other trusted websites, security researchers have warned.

The attacks work by poisoning the domain name system cache that the service providers use to translate domain names such as google.com into internet protocol numbers such as 74.125.224.144. By replacing legitimate IP addresses with ones leading to servers controlled by attackers, the hack is causing end users to be surreptitiously directed to sites that exploit software vulnerabilities on their computers or trick them into installing malware.

“Last week, Brazil's web forums were alive with desperate cries for help from users who faced malicious redirections when trying to access websites such as YouTube, Gmail and Hotmail, as well as local market leaders including Uol, Terra and Globo,” Fabio Assolini, a researcher with antivirus provider Kaspersky Labs, wrote in a blog post published on Monday. “In all cases, users were asked to run a malicious file as soon as the website opened.”

Assolini said the browser of one machine Kaspersky researchers tested displayed a warning when opening www.google.com.br instructing them to install a program called Google Defence.

A display encountered by a Kaspersky researcher reads: "To access the new Google.com, you need to install Google Defence"

DNS cache poisoning is frequently carried out by exploiting long-standing security vulnerabilities in the DNS, but at least some of the recent attacks in Brazil appear to be the result of a rogue insider at one of the targeted ISPs.

According to Assolini, a 27-year-old employee of a medium-sized provider in the south of the country has been arrested and accused of participating in the malicious scheme. The researcher provided no other details, except to say that over a 10-month period the unnamed employee had changed the DNS cache of the ISP, redirecting all users to phishing websites.

Assolini also said companies are reporting attacks that are changing the DNS configurations of their routers and modems. As a result, when employees try to visit websites, they encounter displays that instruct them to install a malicious Java applet.

"As described by my colleague Marta in this analysis, several routers and modems have security flaws that enable an external attacker to access and change the configuration of the device,” Assolini wrote. “They are able to exploit security failures and vulnerable configurations such as default passwords.”

In many cases, the malware being pushed on victims is a trojan that steals online banking credentials. ®

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.