Antimalware and cybersecurity portal - Windows Defender Security Intelligence

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BREAKING NEWS: Windows Defender Advanced Threat Protection (Windows Defender ATP) to include AI-driven automated investigation and remediation capabilities later this year.Learn more

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Explore our in-depth threat encyclopedia for information about threat types and specific malware

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Enable Windows Defender Antivirus
Keep your PC safer with the free, trusted antivirus protection built in to Windows 10.
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Sign up for Windows Defender ATP
Detect, investigate, and respond to targeted attacks in the enterprise using cloud-based behavioral analytics.
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Get Microsoft Security Software
Stay safer with the right security software that works effectively with Windows.
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Boost defenses with Windows Defender Exploit Guard
Get enhanced protection against ransomware and advanced attacks involving exploits, tainted documents and scripts, and code injection.
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Troubleshoot malware detection and removal
Resolve problems with detecting and removing persistent threats.
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Visit the help center
Explore our collection of helpful security advice to keep your computers safe.
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