Analysis of active exploitation of SolarWinds Web Help Desk

The Microsoft Defender Research Team observed a multi‑stage intrusion where threat actors exploited internet‑exposed SolarWinds Web Help Desk WHD instances to get an initial foothold and then laterally moved towards other high-value assets within the organization. However, we have not yet confirm...

Widespread malware campaign seeks to silently inject ads into search results, affects multiple browsers

A persistent malware campaign has been actively distributing an evolved browser modifier malware at scale since at least May 2020. At its peak in August, the threat was observed on over 30,000 devices every day. The malware is designed to inject ads into search engine results pages. The threat...

Defending Exchange servers under attack

Securing Exchange servers is one of the most important things defenders can do to limit organizational exposure to attacks. Any threat or vulnerability impacting Exchange servers should be treated with the highest priority because these servers contain critical business data, as well as highly...

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...

RKDetect - behaviour based rootkit detection utility

Rkdetect is a little anomaly detection tool which can find services hidden by generic Windows rootkits like Hacker Defender. Tool very simply. It enumerates services on remote computer through WMI user level and Services Control Manager kernel level, compare result and display difference. In this...