Microsoft Defender Antivirus vs Surfshark Antivirus Comparison

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

• Surfshark One, renewal: $99 a year after the first term, whether that term was 1 or 2 years
• Surfshark One, month to month: $19.95 billed every month, no discount
• Surfshark One, first 2 years: Intro: $67.23 for the first 27 months (24 plus 3 bonus months), then $99 a year
• Surfshark One, first year: Intro: $44.85 for the first 15 months (12 plus 3 bonus months), then $99 a year
• Surfshark One+, renewal: $119 a year after the first term

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.

Surfshark says Cloud Protect checks suspicious files against its cloud database in real time 'without ever seeing your personal data', but neither the product pages, the help center nor the privacy policy say whether a file's fingerprint or the file itself is sent.

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.

The privacy policy's antivirus section uses device information to enforce the device limit and processes the malware name and type, country, OS and user ID for statistics. Separately, with your consent, the apps send device and engagement data to analytics and attribution providers, and the policy says advertising partners help attribute sales and show interest-based ads. The policy says Surfshark does not sell personal data.

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.

The contract is with Surfshark B.V., registered in Amsterdam, the Netherlands. The terms of service are governed by the law of the British Virgin Islands.

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.

Surfshark B.V. sells the antivirus as part of its own subscription. The privacy policy says it shares data with its group companies in the EEA, the United States and the United Kingdom, without naming them.