Kaspersky Premium vs Microsoft Defender Antivirus Comparison

• Standard for 3 devices, renewal: $34.99 a year, the renewal price the store states
• Standard for 3 devices, first year: Intro: $30.99 for the first year
• Plus for 3 devices, renewal: $46.99 a year, the renewal price the store states
• Plus for 3 devices, first year: Intro: $40.99 for the first year
• Premium for 3 devices, renewal: $54.99 a year, the renewal price the store states
• Premium for 3 devices, first year: Intro: $42.99 for the first year

• Included in Windows: Built into Windows; not sold separately

The products and services privacy policy lists what the software can send to Kaspersky: threats detected, information on installed applications, the addresses of websites visited (logins and passwords removed up to the host name), operating system events, Wi-Fi connection data and, in its words, suspicious files that 'can be automatically sent for a more thorough analysis by machine learning-based technologies and, in rare cases, by a malware analyst'. The files are mainly executables; harmless files or parts of them may be sent too, to reduce false positives. The policy says the Kaspersky Security Network Statement and the Marketing Statement list data that users decide to provide by ticking a box in the product settings. Kaspersky says files shared by users in Europe, North and Latin America, the Middle East and several Asia-Pacific countries are processed in two data centres in Zurich, Switzerland.

Cloud-delivered protection is on by default. When the app cannot decide about a file on the device, it sends the file's metadata to Microsoft: hashes, file name and size, signer, the process that touched it, the download address and IP, the hashed file path, and the device's OS version, locale and geographical location. If that is not enough, Microsoft can request the file itself. The default setting sends 'safe samples' such as .exe, .dll and .bat files automatically and asks you before sending a file likely to contain personal data. You can switch off sample submission or cloud-delivered protection in Windows Security; Microsoft's documentation says detection metadata is still sent when sample submission is off.

The privacy policy says data is used to protect users, to update the antivirus databases, to analyse threats, and to improve products through 'statistical research and analyses' on de-identified data. It also lists 'personalized information and offers from Kaspersky, including ... Kaspersky and third-party products and services, marketing offers, discounts'. Kaspersky may share data within its group and with service providers that supply 'web analytics, data processing, advertising, e-mail distribution, payment processing, order fulfillment'. On Android it processes a hash of a device identifier. The policy version opened is dated 28 February 2022. It states that data can be processed in Russia, China and Belarus among other countries, and that data from users in the EU is processed 'on servers located in the EU and Russia'.

Microsoft's privacy statement says Defender Antivirus automatically sends reports about suspected malware and unwanted software and may send files for inspection, asking first if a report may contain personal data. Windows required diagnostic data, which includes a Defender health event with a Defender machine ID, is stored with unique identifiers and used to keep Windows secure and to improve Windows. If you turn on the Windows setting Personalized offers, Windows diagnostic data is also used for tips, ads and recommendations. The statement also says Microsoft discloses personal data for digital advertising, and in response to valid legal process from law enforcement and government agencies.

Controls over how Kaspersky develops, tests and releases the antivirus databases for Windows and Unix systems, August 2025 to July 2026

Kaspersky calls itself a private international company with its holding company, Kaspersky Labs Limited, in the United Kingdom, and its operating company, AO Kaspersky Lab, in Russia. The privacy policy is issued by AO Kaspersky Lab, Moscow, and names Kaspersky Labs GmbH in Ingolstadt, Germany, as the group's representative for EU data protection law. The US Commerce Department's 2024 entity listing names AO Kaspersky Lab and OOO Kaspersky Group in Russia and Kaspersky Labs Limited in the United Kingdom. Kaspersky says it has no ties to the Russian government and is not obliged to hand over user information under Russian surveillance laws; the Commerce Department found that it 'is subject to the jurisdiction of the Russian Government and must comply with requests for information'.

Microsoft Corporation, One Microsoft Way, Redmond, Washington, is the data controller; for the European Economic Area, the UK and Switzerland it is Microsoft Ireland Operations Limited in Dublin. Microsoft takes part in the EU–US, UK and Swiss data privacy frameworks.

Kaspersky was founded in 1997 and has its headquarters in Moscow. It describes itself as privately held; neither its privacy policy nor its FAQ names the owners of the UK holding company. The US Treasury sanctioned twelve board members and senior executives of AO Kaspersky Lab in June 2024; Kaspersky states that neither the company, its subsidiaries nor its chief executive was designated.

Microsoft was founded in 1975 and trades on the stock market as MSFT. Its antivirus began in 2009 as Microsoft Security Essentials, became Windows Defender in Windows 8 and 10, and was renamed Microsoft Defender Antivirus in 2020.