Screenshot of obfuscated script

Out of sight but not invisible: Defeating fileless malware with behavior monitoring, AMSI, and next-gen AV

Removing the need for files is the next progression of attacker techniques. While fileless techniques used to be employed almost exclusively in sophisticated cyberattacks, they are now becoming widespread in common malware, too. The post Out of sight but not invisible: Defeating fileless malware with behavior monitoring, AMSI, and next-gen ... Read More
Protecting the modern workplace from a wide range of undesirable software

Protecting the modern workplace from a wide range of undesirable software

Security is a fundamental component of the trusted and productive Windows experience that we deliver to customers through modern platforms like Windows 10 and Windows 10 in S mode. As we build intelligent security technologies that protect the modern workplace, we aim to always ensure that customers have control over ... Read More

Sharing research and discoveries at PWN2OWN

The annual PWN2OWN exploit contest at the CanSecWest conference in Vancouver, British Columbia, Canada, brings together some of the top security talent from across the globe in a friendly competition. For the participants, these events are a platform to demonstrate world-class skills and vie for significant cash prizes. For companies ... Read More
Poisoned peer-to-peer app kicked off Dofoil coin miner outbreak

Poisoned peer-to-peer app kicked off Dofoil coin miner outbreak

On March 7, we reported that a massive Dofoil campaign attempted to install malicious cryptocurrency miners on hundreds of thousands of computers. Windows Defender Antivirus, with its behavior monitoring, machine learning technologies, and layered approach to security detected and blocked the attack within milliseconds.Windows 10 S, a special configuration of ... Read More
Figure 1: Windows Defender ATP machine timeline view with Windows Defender Exploit Guard event

Behavior monitoring combined with machine learning spoils a massive Dofoil coin mining campaign

Just before noon on March 6 (PST), Windows Defender AV blocked more than 80,000 instances of several sophisticated trojans that exhibited advanced cross-process injection techniques, persistence mechanisms, and evasion methods. Behavior-based signals coupled with cloud-powered machine learning models uncovered this new wave of infection attempts. The trojans, which are new ... Read More

#AVGater vulnerability does not affect Windows Defender Antivirus, MSE, or SCEP

On November 10, 2017, a vulnerability called #AVGater was discovered affecting some antivirus products. The vulnerability requires a non-administrator-level account to perform a restore of a quarantined file. Windows Defender Antivirus and other Microsoft antimalware products, including System Center Endpoint Protection (SCEP) and Microsoft Security Essentials (MSE), are not affected ... Read More