Sophos

Sophos was founded by Jan Hruska and Peter Lammer and began producing its first antivirus and encryption products in 1985. During the late 1980s and into the 1990s, Sophos primarily developed and sold a range of security technologies in the UK, including encryption tools available for most users (private or business). In the late 1990s, Sophos concentrated its efforts on developing and selling antivirus technology and embarked on a program of international expansion.

In 2010, the majority interest of Sophos was sold to Apax Partners.

In 2011, Utimaco Safeware AG (acquired by Sophos in 2008) was accused of supplying data monitoring and tracking software to partners that have sold to governments such as Syria. Sophos issued a statement of apology and confirmed that it had suspended its relationship with the partners in question and launched an investigation.

In June 2015, Sophos announced plans to raise US$100 million on the London Stock Exchange. Sophos was floated on the FTSE in September 2015.

On 14 October 2019, Sophos announced that Thoma Bravo, a US-based private equity firm, made an offer to acquire Sophos for US$7.40 per share, representing an enterprise value of approximately US$3.9 billion. The board of directors of Sophos stated their intention to recommend the offer to the company's shareholders unanimously. On 2 March 2020, Sophos announced the completion of the acquisition.

In February 2024, President Joe Levy was appointed acting CEO after Kris Hagerman resigned from the CEO position. Mr. Levy was named the permanent CEO in May 2024.

In October 2024, Sophos released a report about its Pacific Rim counter-offensive operation, detailing actions taken against China-based adversaries along with additional information concerning this effort. It was reported by Wired that the company had been targeted for years by hackers affiliated with the University of Electronic Science and Technology of China and Sichuan Silence Information Technology, a company associated with China's Ministry of Public Security. The attacks were attributed to Chinese advanced persistent threats such as APT41, APT31, and Volt Typhoon. The Federal Bureau of Investigation (FBI) asked for the public's help in identifying the attackers.

In 2003, Sophos acquired ActiveState, a Canadian software company that developed anti-spam software. From September 2003 to February 2006, Sophos served as the parent company of ActiveState, a developer of programming tools for dynamic programming languages: in February 2006, ActiveState became an independent company when it was sold to Vancouver-based venture capitalist firm Pender Financial.

In 2007, Sophos acquired ENDFORCE, a company based in Ohio, United States, which developed and sold security policy compliance and network access control (NAC) software.

In July 2008, Sophos agreed to acquire Utimaco, a publicly-held company focused on encryption and other data security products, for over $340 million; the acquisition closed for $314 million in September 2008. In October 2013, Utimaco was divested via a management buyout involving investors PINOVA Capital and BIP Investment Partners.

In May 2011, Sophos announced the acquisition of Astaro, a privately held provider of network security products, headquartered in Wilmington, Massachusetts, USA and Karlsruhe, Germany. At the time Astaro was the 4th largest UTM (Unified Threat Management) vendor and while the deal made sense at the time Forbes questioned its viability. Sophos subsequently renamed the Astaro UTM to Sophos UTM.