Avast Antivirus is a family of cross-platform internet security applications developed by Avast for Microsoft Windows, macOS, Android, and iOS. Avast offers free and paid products that provide computer security, browser security, antivirus software, firewall, anti-phishing, antispyware, and anti-spam, among other services.Avast launched a freeware business product, Avast for Business, in February 2015. It includes antivirus protection, web threat scanning, browser protection, and a cloud management console.As of 2017, Avast is the most popular antivirus vendor on the market, and it had the largest share of the market for antivirus applications.In January 2020, multiple news sources reported that Avast Antivirus, through a subsidiary, was selling the browsing history of Avast Free product users. Though the company claimed all data was "de-identified", it was reported that the sold data could possibly in some instances be linked back to people's real identities, exposing every click and search they had made. In response, Avast announced that it would close the subsidiary over the data privacy backlash.