Microsoft Defender Antivirus

Microsoft Defender Antivirus
Other namesWindows Defender Windows Security
Original author(s)Microsoft
Developer(s)Microsoft
Stable release(s) [±]
PlatformMay 2025 Update (4.18.25050.5) / 13 June 2025 (2025-06-13)
Windows appMay 2025 Update (102.2505.23001.0) / 18 June 2025 (2025-06-18)
iOS1.1.6528.0104 / 3 June 2025 (2025-06-03)
Android1.0.7801.0101 / 4 June 2025 (2025-06-04)
Operating system
PlatformWindows
PredecessorMicrosoft Security Essentials
TypeAntivirus software, personal firewall, parental control, intrusion prevention, email filtering and anti-phishing
LicenseProprietary

Microsoft Defender Antivirus (formerly Windows Defender) is an antivirus software component of Microsoft Windows. It was first released as a downloadable free anti-spyware program for Windows XP and was shipped with Windows Vista and Windows 7. It has evolved into a full antivirus program, replacing Microsoft Security Essentials in Windows 8 or later versions.

In March 2019, Microsoft announced Microsoft Defender ATP for Mac for business customers to protect their Mac devices from attacks on a corporate network, and a year later, to expand protection for mobile devices, it announced Microsoft Defender ATP for Android and iOS devices, which incorporates Microsoft SmartScreen, a firewall, and malware scanning. The mobile version of Microsoft Defender also includes a feature to block access to corporate data if it detects a malicious app is installed.