Cybercriminals are abusing a European law on the use of web Browser cookies to trick users into clicking on a fake notification alert that actually hides a legitimate digital ad, Malwarebytes security researchers warn.
The EU Directive was adopted in May 2011, when the European Parliament required that users be provided with the possibility to refuse the use of cookies. As a result, website owners are required to display a notification on their sites to inform visitors from the European Union region that cookies are used, with some sites actually displaying these notifications to people coming from all regions.
The cookie law was based on the idea that cookies reduce the online privacy of users, as they store information on people’s web browsing habits. While some of these cookies make the browsing experience more personal, they can also collect data across many websites to create ‘behavioral profiles’ of people.
Based on the Cookie Law, which was designed to protect users’ online privacy, websites need to get consent from visitors to store or retrieve any information on their computers, smartphones or tablets, and this is what bad actors are abusing as part of the newly discovered clickjacking campaign.
As Malwarebytes’ Jérôme Segura explains in a blog post, the fake notification alerts used in this campaign actually hide a legitimate advertisement. Thus, the cybercriminals are abusing both the advertiser and the ad network that is hosting the ad.
The fraudsters managed to successfully load an ad banner via an iframe on top of the warning message, yet the ad is invisible to users, as one of the parameters in the iframe sets its opacity to zero. Thus, when the user clicks anywhere on the notification message, it acts as it they actually clicked on the ad banner, which loads the advertiser’s website.
This simple clickjacking technique is highly effective at generating clicks that appear to be perfectly legitimate and performed by real human beings instead of bots. Although users are not directly impacted by this campaign, the fraudulent operation costs both advertisers and ad networks a lot of money, while cybercriminals profit from the fake Pay-Per-Click traffic, Segura explains.
The ad network involved in this fraudulent campaign is popcash.net, while the affected domains are featurewebhosting(.)com, elitewebhostings(.)com, bestcartoday(.)info, hotcartop(.)online, and ivirtualcloudhost(.)com.
Malwarebytes said it has informed Google about the fraudulent scheme.
Clickjacking vulnerabilities affect even some of the most popular websites, a recent example being a flaw patched by LinkedIn in November 2015. However, website owners and service providers can prevent clickjacking in various ways, as Chris Hinkley explained in a SecurityWeek column several years ago.
Related Reading: Cookies Render HTTPS Sessions Vulnerable to Data Leaks