Feeds

No relief from Microsoft phishing bug

Avoid the hyperlinks!

  • alert
  • submit to reddit

Seven Steps to Software Security

Tuesday's edition of Microsoft's monthly bundle of security advisories features an omission that should keep online fraud artists and identity thieves happy: over one month after its discovery, there is no official patch available for a bug in Internet Explorer that lets swindlers pass off counterfeit websites as the real thing.

The bug, publicly detailed on December 9th by "Zap the Dingbat," is an easily exploited flaw in the way Internet Explorer displays URLs in the address bar: it turns out the browser is incapable of displaying the special character "%01," or anything following it, in a Web address.

That simple gaffe is tailor-made for the devious online swindle called "phishing," in which a fraudster spams the Internet with e-mail purporting to be from a reputable financial institution or e-commerce site, and urging the recipient to click on an included link to update their personal profile or carry out some transaction. The link takes the victim to a fake website designed -- with increasing sophistication -- to look like the real deal, but where any personal or financial information entered is routed directly to the scammer.

Experts have traditionally advised consumers to avoid these scams by carefully checking the address bar in their browser window to verify that they're actually on citibank.com, for example, before entering their password or account information. But the IE bug makes that advice obsolete: combined with URL obfuscation techniques already well known to phishers, IE helpfully transforms a clumsy fake like "www.citibank.com%01@211.239.150.170/login/login.htm" into the flawless counterfeit "www.citibank.com."

It took scammers a full week to begin taking advantage of the bug, says Dan Maier, director of marketing for the Anti-Phishing Working Group, but when they caught on, they were fully incorporated the dodge into their bag of tricks. PayPal and Earthlink customers the first targets of the enhanced swindle. "There's one we saw that was very sophisticated attacking Earthlink customers," says Maier. "It brought them back to an Earthlink-branded website which asked for a scary amount of personal information, and the most frightening part of it was that the URL said earthlink.net."

Now financial institutions are the target of choice. A fraudulent e-mail received at SecurityFocus last week used the hole in directing recipients to a convincing reproduction of a Bank of America site, asking for an account number and pass code for BofA's online banking service. On Monday, Citibank warned of a fresh batch of phishing e-mails tempting victims by urging them to check their account balances, also using the bug. And Barclays and Lloyds have reported scammers using the vulnerability in recent UK-focused phishing expeditions.

But Russ Cooper, moderator of the NTBugtraq list and "Surgeon General" of TruSecure Corporation, says the impact of the IE bug is easily overstated: most victims of phishing scams would have fallen for the ruse even without the added cloaking provided by the bug. "There's a limited amount of people who would be subjected to this particular attack who wouldn't already give their information to an even dumber version of this attack," says Cooper.

In a statement, a Microsoft spokesperson said the company will only release a patch "that is as well engineered and thoroughly tested as possible -- whether that [takes] a day, week, month or longer." Under Redmond's monthly schedule, the next batch of security fixes is due February 10th. But an article on Microsoft's website offers consumers an easy, if drastic, workaround in the meantime: simply abandon the whole hypertext thing altogether. "The most effective step that you can take to help protect yourself from malicious hyperlinks is not to click them," the company advises. "Rather, type the URL of your intended destination in the address bar yourself."

"Which means never follow hyperlinks on the Web," Cooper says with a laugh. "What was the Web for then?"

Copyright © 2004, SecurityFocus logo

Mobile application security vulnerability report

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
Attackers raid SWISS BANKS with DNS and malware bombs
'Retefe' trojan uses clever spin on old attacks to grant total control of bank accounts
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
prev story

Whitepapers

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.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
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.