Chrome and Firefox Browser Extensions Steals Browsing Web Histories From Over 4M Users
July 21, 2019 Share

Chrome and Firefox Browser Extensions Steals Browsing Web Histories From Over 4M Users


DataSpii a new privacy issue which puts millions of people browsing histories under risk. The term was coined and researched by security researcher Sam Jadali, he discovered eight such browser extensions that harvested over 4 million Firefox and Chrome users data.

The browser extensions collect sensitive data in real-time, that includes personally identifiable information (PII) and corporate information (CI). The data primarily impact Firefox and Chrome users because of eight invasive extensions.

These extensions collect the URLs, webpage titles, LAN IPs, hostnames, web server technology data and even embedded hyperlink in the web pages. Dan Goodin at Ars Technica reported that these collected data are published to fee-based service called Nacho Analytics.

Links Published into Nacho Analytics

The investigation started after Jadali found a set of links published into Nacho analytics that associated with one of his client domains and the links appeared to private conversations.

Jadali suspected that these links will be collected by some browser extensions, he analyzed more than 200 extensions including Hover Zoom, but none of the extension sends data to Nacho analytics.

Later he compared the Nacho Analytics timestamp with his server logs that monitor client domains, which indicates that two of three users having Hover Zoom extension added to the browser.

Extension Analysis & Data Collection Activity

Later Jadali setup an extension analysis lab with the clean OS, Burp Suite to analyze the web traffic and FoxyProxy that proxies Chrome requests to Burp Suite. “Also performed a quantitative text and source code analysis of each extension author’s website, including the extension’s terms of service and privacy policy pages.”

Click to enlarge

With Hover Zoom analysis, after the extension installation, it performs the first update and no data is collected at that point, followed by the first update, the second update comes after 24 days after installation.

Following to the second update immediately a GET request sent from the extension server that steals the browser activity data and sent via a POST request.

Jadali tested with VM changes, “We browsed several sites, including 10 pages on After we visited those pages, we observed a POST request to The payload contained compressed and encoded data of our browsing activity.”

To decode the data they used DataSpii decoder tool and the tool now available for public use, following are the extension appeared to be collecting data and posted on Nacho Analytics.

Hover Zoom – To enlarge images
SpeakIt – Text to speech converter
SuperZoom – Zoom in on images Helper – To download video and music
FairShare Unlock – Advertised as accessing premium content for free
PanelMeasurement – Finding market research surveys
Branded Surveys – Offers cash for completing the survey
Panel Community Surveys – Offers cash for answering online surveys.

Data at Risk – DataSpii

According to the report, it affects both personal and corporate data. The following are the personal data at risk personal interests, tax returns, GPS location, cloud services, and data, file attachments, credit card information, genetic profiles, travel itineraries, genealogy, and online shopping history.

Following are the corporate data affected the real-time activity of employees, including the corporate tasks they were assigned, private LAN network structure, partial page content (includes hyperlinks embedded on a LAN website), company memos, API keys, proprietary source code, firewall access codes, proprietary secrets, operational material and zero-day vulnerabilities.

How to find if I am Impacted with DataSpii?

You can check with chrome://extensions or Firefox addons about:addons to see if you have any extension installed if you have any of the extension it is recommended to remove them.

Jadali has reported the findings to Google, Mozilla, and Opera, they are to remotely disable the identified extensions. All the operating systems running that are running the browsers are affected.

Previously a number of Chrome extensions caught stealing Facebook data, users location and browsing histories of millions of users.

It is recommended to use the extension only if it is mandatory, even that too after analyzing the behaviors of it.

This post Chrome and Firefox Browser Extensions Steals Browsing Web Histories From Over 4M Users originally appeared on GB Hackers.

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