Vulnerability allows scammers to hijack pop-ups

Security researchers warned this week of a vulnerability in most Web browsers which could potentially allow scammers to launch phishing attacks from pop-up windows on trusted Web sites.

The vulnerability arises when an Internet user opens browser windows for both a legitimate Web site and a malicious site at the same time. Because of an old functionality that exists in most browsers, the malicious site can potentially display information in a pop-up window from the trusted site, according to Secunia Research.

The vulnerability has yet to be exploited but could present a very effective method for launching online fraud scams, often known as phishing, Secunia Chief Technology Officer Thomas Kristensen said Thursday.

While most users do not intentionally visit malicious Web sites, they often stumble upon them by following links, making it relatively common for Net surfers to have browser windows open for both legitimate and malicious sites at the same time, Kristensen said.

This could be a particularly dangerous situation if exploited to display misleading information on a pop-up window from a legitimate bank Web site, for example, he warned. Even if savvy users check for a the yellow "lock" icon on a Web site, signifying encryption, the pop-up could still display content from the malicious site, he said.

"This could be a surprisingly effective way to seduce or trick people into doing something," Kristensen said.

The vulnerability affects almost all browsers, including Internet Explorer (IE), Mozilla, Firefox, Opera, Konqueror, Safari and Netscape, the researcher said.

Secunia, based in Copenhagen, went public with its warning Wednesday, after saying that it had alerted browser vendors of the vulnerability months ago.

Microsoft said Thursday that it has investigated the report, and customers who use Windows XP SP2 and follow its advice on spoofing attacks are at a reduced risk.

The functionality described in the report allows a Web site to open or re-use a window without displaying the address bar. However, SP2 users will see a status bar in the pop-up window, allowing them to look for the yellow lock icon and confirm that the site is valid, Microsoft said.

Opera has also included measures to mitigate the vulnerability in the latest beta version of its software, Kristensen said.

He acknowledged that by going public with the warning he was also alerting Internet scammers to a new opportunity, but said that he felt the public should be aware of the threat since not all browser vendors had been responsive.

"We thought it would be better to openly talk about this and we are giving advice on how to mitigate it," Kristensen said.

Join the newsletter!


Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Scarlet Pruitt

IDG News Service
Show Comments

Brand Post

Most Popular Reviews

Latest Articles


PCW Evaluation Team

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?