Feeds

Cache-poisoning attack snares top Brazilian bank

Google Adsense spoofed

Secure remote control for conventional and virtual desktops

One of Brazil's biggest banks has suffered an attack that redirected its customers to fraudulent websites that attempted to steal passwords and install malware, according to an unconfirmed report.

According to this Google translation of an article penned in Portuguese, the redirection of Bradesco was the result of what's known as a cache poisoning attack on Brazilian internet service provider NET Virtua.

DNS cache poisoning attacks exploit weaknesses in the internet's domain name system. ISPs that haven't patched their systems against the vulnerabilities are susceptible to attacks that replace the legitimate IP address of a given website with a fraudulent number. End users who rely on the lookup service are then taken to malicious websites even though they typed the correct domain name into their browser.

"That's pretty serious when you're talking about a banking organization," said Paul Ferguson, a security researcher with anti-virus provider Trend Micro. "If people are trying to log in to their account and they get rejected, they'll try again and again with the same user name and password."

DNS cache poisoning has been around since the mid 1990s, when researchers discovered that DNS resolvers could be flooded with spoofed IP addresses for sensitive websites. The servers store the incorrect information for hours or days at a time, so the attack has the potential to send large numbers of end users to fraudulent websites that install malware or masquerade as a bank or other trusted destination and steal sensitive account information.

In 1998, Eugene E. Kashpureff admitted to federal US authorities that on two occasions the previous year he used cache poisoning to divert traffic intended for InterNIC to AlterNIC, a competing domain name registration site that he owned.

Makers of DNS software were largely able to prevent the attacks by adding pseudo-random transaction ID numbers to lookup requests that must be included in any responses. Then, last year, IOActive researcher Dan Kaminsky revealed a new way to poison DNS caches, touching off a mad scramble by the world's ISPs to fix the vulnerability before it was exploited.

The article from Globo.com cited a Bradesco representative who said that about 1 percent of the bank's customers were affected by the attack. It went on to suggest that customers who were paying attention would have noticed Bradesco's secure sockets layer certificate generated an error when they were redirected to the fraudulent login page.

Interestingly, it also said that a domain used for Google Adsense was redirected to a site that used malicious Javascript to install malware redirected machines. The attacks have since been resolved, the article stated.

It's still not clear exactly how the caches were tainted. Representatives for the ISP and the bank hadn't responded to requests for comment at time of publication. ®

This story was updated to spell the name of the bank that was attacked.

Choosing a cloud hosting partner with confidence

More from The Register

next story
Webcam hacker pervs in MASS HOME INVASION
You thought you were all alone? Nope – change your password, says ICO
You really need to do some tech support for Aunty Agnes
Free anti-virus software, expires, stops updating and p0wns the world
Meet OneRNG: a fully-open entropy generator for a paranoid age
Kiwis to seek random investors for crowd-funded randomiser
USB coding anarchy: Consider all sticks licked
Thumb drive design ruled by almighty buck
Attack reveals 81 percent of Tor users but admins call for calm
Cisco Netflow a handy tool for cheapskate attackers
Patch NOW! Microsoft slings emergency bug fix at Windows admins
Vulnerability promotes lusers to domain overlords ... oops
prev story

Whitepapers

Choosing cloud Backup services
Demystify how you can address your data protection needs in your small- to medium-sized business and select the best online backup service to meet your needs.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Getting ahead of the compliance curve
Learn about new services that make it easy to discover and manage certificates across the enterprise and how to get ahead of the compliance curve.
Intelligent flash storage arrays
Tegile Intelligent Storage Arrays with IntelliFlash helps IT boost storage utilization and effciency while delivering unmatched storage savings and performance.