Avast Software s.r.o., one of the world’s largest antivirus providers, has decided to shut down one of its subsidiaries after an exposé revealed that the group sold data on users’ web activity to marketers.

Avast Chief Executive Officer Ondrej Vlcek announced the move on the company’s blog this morning. The subsidiary at the center of the controversy, Jumpshot, is a marketing analytics business with six offices worldwide that the antivirus provider launched in 2015. Ondrej wrote that Avast has halted the unit’s data collection operations and will start the process of winding it down.

A joint Motherboard-PCMag investigation published this week revealed that Jumpshot was selling information collected by Avast’s antivirus products on users’ browsing habits. The unit supplied companies such as Home Depot Inc., PepsiCo Inc. and Microsoft Corp. with anonymized copies of consumers’ browsing histories as well as information about their activity on popular websites. The information included data points ranging from what videos users watched on YouTube to items they purchased on Amazon.

The scope of the data harvesting was likely broad. Jumpshot claimed on its website to have access to information from 100 million devices, while parent Avast’s security products counts more than 435 million active monthly users globally.

Vlcek apologized to users in his blog post announcing Jumpshot’s closure today. “As CEO of Avast, I feel personally responsible and I would like to apologize to all concerned,” the executive wrote.

Vleck went on to stress that “Jumpshot has operated as an independent company from the very beginning, with its own management and board of directors,” while arguing that “both Avast and Jumpshot acted fully within legal bounds.” Even so, the revelation may draw scrutiny to Prague-based Avast from European competition authorities, who have taken a tough stance against large tech companies in recent years when it comes to privacy issues.

The potential severity of Jumpshot’s data selling means that regulators might potentially be driven to take a closer look at other antivirus providers as well. Such a broad, multicompany investigation wouldn’t be a first for the tech industry. In the middle of last year, the House Judiciary Committee launched an antitrust probe of Google LLC, Facebook Inc., Amazon.com Inc. and Apple Inc. to determine if they may have violated competition laws.

As for Avast, the antivirus provider is already feeling the impact of the data gathering scandal. The company’s stock is down more than 25% on the London Stock Exchange since the start of the week.

Photo: Avast