Sneaky browser 'tabnapping' phishing tactic surfaces
Mozilla outlines how hackers can trick users by silently changing open browser tabs
Computerworld - A Mozilla employee yesterday outlined a sly new attack tactic dubbed "tabnapping" that can dupe users into giving up passwords by secretly changing already-open browser tabs.
All of the major browsers on Windows and Mac OS X are vulnerable to the attack.
Aza Raskin, Firefox's creative lead, spelled out the scenario, which is striking in its assumption: Most people keep multiple tabs open, often for long periods.
"As the user scans their many open tabs, the favicon and title act as a strong visual cue -- memory is malleable and moldable and the user will most likely simply think they left a Gmail tab open," said Raskin, referring to his example of a spoofed Google Gmail log-in. "When they click back to the fake Gmail tab, they'll see the standard Gmail log-in page, assume they've been logged out, and provide their credentials to log in."
There's no need for the attacker to change the actual URL that shows in the browser's address bar, since the tactic banks on the trust that tabs can't suddenly mutate. "The attack preys on the perceived immutability of tabs," Raskin said.
Raskin also laid out several ways hackers could boost tabnapping's sneakiness, ranging from sniffing out sites that the victim actually visits -- put up a fake Facebook log-in, say, rather than simply betting that the user opens Gmail -- to changing the text on the bogus page. "You can mention that the session has timed out and the user needs to re-authenticate," Raskin said. "This happens often on bank Web sites, which makes them even more susceptible to this kind of attack."
Computerworld ran Raskin's proof-of-concept -- his blog post explaining the attack includes the necessary code -- and found that Chrome, Firefox, Opera and Safari in Mac OS X 10.6 all showed the fake Gmail tab and contents. In Windows XP, Chrome, Firefox, Internet Explorer and Opera did the same.
But some browsers were more susceptible than others. In both Windows and Mac OS X, for instance, Raskin's code changed only Firefox's "favicon," the small icon that typically shows a miniature site logo. In other browsers, the favicon for Raskin's blog remained, though the label and content was that of Gmail.
Google's Chrome seemed especially resilient to the tactic. On the Mac, Raskin's trick sometimes changed the tab, often did not. Computerworld was not able to nail down the specific situations when Chrome fell victim, however.
Raskin did not reply to questions about what steps Firefox and other browser makers might take to stymie such attacks. In his blog, Raskin touted ongoing work on a new username/password tool called "Account Manager" that is tentatively slated to show up in Firefox 4, the ambitious upgrade Mozilla plans to release this November.
Andrew Storms, director of security operations at nCircle Security, doubted whether there is an easy fix. "I can't think of anything off hand that could be done," Storms said via instant message. "That's the part of the new dynamic nature of Web browsing. You can alter the look/feel of the experience for both good and bad."
Jerry Bryant, a group manager with the Microsoft Security Response Center (MSRC), said his team is looking into Raskin's claims, but hinted that Microsoft wouldn't be patching IE anytime soon. "I wouldn't classify this as a 'vulnerability' though," Bryant said in an e-mail answer to questions.
When Microsoft declines to name an issue a security vulnerability, it generally means that if a fix does come, it won't appear until a service pack or next major upgrade is released. In the case of Internet Explorer, that would be IE9, which remains in the early development stage.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is email@example.com.
- IE6: Retired but not dead yet
- Chrome users won't give up, keep pressing Google to restore old-style new tab page
- Google quashes 31 vulnerabilities, restores Metro mode 'steppers' with Chrome 34
- Firefox's UI face-lift on track for April debut
- Ex-Mozilla engineer blames Microsoft's rules for Metro Firefox's death
- Mozilla patches 20 Firefox flaws, plugs Pwn2Own holes
- Google reverses field, promises to restore Chrome's scrollbar arrows
- Update: Google ships Chrome 33, patches 28 bugs
- Mozilla's top exec defends in-Firefox ads, revenue search
- Mozilla taps in-Firefox ads as it searches for more revenue
Read more about Security in Computerworld's Security Topic Center.
- Radicati: Cloud Business Email - Market Quadrant 2013 Google was named the top cloud business email provider in a recent report by research firm Radicati. Out of 14 key players, Google...
- Tablets in the Enterprise: A Checklist for Successful Deployment How can you enterprise manage and secure tablets in order to protect corporate data while providing access to the information and applications employees...
- Enterprise Mobility: A Checklist for Secure Containerization The advantages and disadvantages of the multiple approaches to containerization. Learn More>>
- Enterprise File Sync & Share Checklist File sync and share has changed the way people work and collaborate in today's tech-savvy world. Gone are the email roadblocks, clunky FTP...
- Live Webcast LIVE EVENT: 5/7, The End of Data Protection As We Know It. Introducing a Next Generation Data Protection Architecture. Traditional backup is going away, but where does this leave end-users?
- LIVE EVENT: 5/7, The End of Data Protection As We Know It. Introducing a Next Generation Data Protection Architecture. Traditional backup is going away, but where does this leave end-users?
- On-demand webinar: "Mobility Mayhem: Balancing BYOD with Enterprise Security" Check out this on-demand webinar to hear Sophos senior security expert John Shier deep dive into how BYOD impacts your enterprise security strategy... All Security White Papers | Webcasts