Avast announced that it would stop providing data to Jumpshot and begin winding down the subsidiary, although it did not give a timeframe. The Jumpshot website is no longer active.

Established in 2015, Jumpshot offered insights on online consumer behaviour through an anonymised panel that tracks actions across devices with Avast anti-virus software installed.

A joint investigation by Vice’s Motherboard and PCMag, published last week, reported that Jumpshot sold browsing data to third-party companies including Microsoft and Google.

Ondrej Vlcek, chief executive of Avast, said: "We are vigilant about our users’ privacy, and we took quick action to begin winding down Jumpshot’s operations after it became evident that some users questioned the alignment of data provision to Jumpshot with our mission and principles that define us as a company."

The decision will affect ‘hundreds’ of Jumpshot employees.

Avast said in an earlier blog post:"We want to reassure our users that at no time have we sold any personally identifiable information to a third party."

Avast established Jumpshot in 2015 with the aim of extending its data analytics offer "beyond core security", and the subsidiary built products and services via the data feed coming from Avast’s anti-virus software, Vlcek said in a separate post.

He said the two companies had operated legally: "During all those years, both Avast and Jumpshot acted fully within legal bounds – and we very much welcomed the introduction of GDPR in the European Union in May 2018, as it was a rigorous legal framework addressing how companies should treat customer data. Both Avast and Jumpshot committed themselves to 100% GDPR compliance."

In July, information company Ascential acquired a 35% minority stake in Jumpshot with the aim of expanding its digital shelf and market share data. Ascential is selling its stake back to Avast, with the latter paying back Ascential for its investments in Jumpshot.