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Microsoft Security

Microsoft Defender Security Research Team Posts

Microsoft Defender Security Research Team

Detonating a bad rabbit: Windows Defender Antivirus and layered machine learning defenses 

Windows Defender Antivirus uses a layered approach to protection: tiers of advanced automation and machine learning models evaluate files in order to reach a verdict on suspected malware. While Windows Defender AV detects a vast majority of new malware files at first sight, we always strive to further close the gap between malware release and […]

New tech support scam launches communication or phone call app 

(Note: Our Tech support scams FAQ page has the latest info on this type of threat, including scammer tactics, fake error messages, and the latest scammer hotlines. You can also read our latest blog, Teaming up in the war on tech support scams.)   A new tech support scam technique streamlines the entire scam experience, […]

Microsoft to remove WoSign and StartCom certificates in Windows 10 

Microsoft has concluded that the Chinese Certificate Authorities (CAs) WoSign and StartCom have failed to maintain the standards required by our Trusted Root Program. Observed unacceptable security practices include back-dating SHA-1 certificates, mis-issuances of certificates, accidental certificate revocation, duplicate certificate serial numbers, and multiple CAB Forum Baseline Requirements (BR) violations. Thus, Microsoft will begin the […]

Links in phishing-like emails lead to tech support scam 

Modern social engineering attacks use non-portable executable (PE) files like malicious scripts and macro-laced documents. Every month, Windows Defender AV detects non-PE threats on over 10 million machines. Learn how machine learning drives next-gen protection capabilities and cloud-based, real-time blocking of new and unknown threats: Machine learning vs. social engineering (Note: Our Tech support scams […]

Windows Defender ATP machine learning: Detecting new and unusual breach activity 

Microsoft has been investing heavily in next-generation security technologies. These technologies use our ability to consolidate large sets of data and build intelligent systems that learn from that data. These machine learning (ML) systems flag and surface threats that would otherwise remain unnoticed amidst the continuous hum of billions of normal events and the inability […]

Windows Defender Antivirus cloud protection service: Advanced real-time defense against never-before-seen malware 

For cybercriminals, speed is the name of the game. It takes newly released malware an average of just four hours to achieve its goal—steal financial information, extort money, or cause widespread damage. In a recent report, the Federal Trade Commission (FTC) said that cybercriminals will use hacked or stolen information within nine minutes of posting […]

Detecting stealthier cross-process injection techniques with Windows Defender ATP: Process hollowing and atom bombing 

Advanced cyberattacks emphasize stealth and persistence: the longer they stay under the radar, the more they can move laterally, exfiltrate data, and cause damage. To avoid detection, attackers are increasingly turning to cross-process injection. Cross-process injection gives attackers the ability to run malicious code that masquerades as legitimate programs. With code injection, attackers don’t have […]

Published
8 min read

Exploring the crypt: Analysis of the WannaCrypt ransomware SMB exploit propagation 

On May 12, there was a major outbreak of WannaCrypt ransomware. WannaCrypt directly borrowed exploit code from the ETERNALBLUE exploit and the DoublePulsar backdoor module leaked in April by a group calling itself Shadow Brokers. The trend towards increasingly sophisticated malware behavior, highlighted by the use of exploits and other attack vectors, makes older platforms […]