Defensive Techniques: Application Guard

Earlier this year, I mentioned that I load every phishing URL I’m sent to see what it does and whether it tries to use any interesting new techniques. While Edge’s “Enhanced Security Mode” reduces the risks of 0-day attacks against the browser itself, another great defense available for enterprise users is Microsoft Defender Application Guard.Continue reading “Defensive Techniques: Application Guard”

SmartScreen Application Reputation, with Pictures

Last Update: Sept 3, 2025 I’ve previously explained how Chromium-based browsers assign a “danger level” based on the type of the file, as determined from its extension. Depending on the Danger Level, the browser may warn the user before a file download begins in order to confirm that the user really wanted a potentially-dangerous file.Continue reading “SmartScreen Application Reputation, with Pictures”

Attack Techniques: QR Codes

As outlined in earlier posts in this series, attackers know that security software can detect their phishing lures and block users from even seeing the lure if it contains a known-phishing URL. For example, both Windows Live and Gmail block email that is believed to contain phishing links. If your enterprise uses Microsoft Defender forContinue reading “Attack Techniques: QR Codes”

Enforcing SmartScreen with Policy

Microsoft Defender SmartScreen provides protection against the most common forms of attack: phishing and malware. SmartScreen support is built-in to Microsoft Edge and the Windows 8+ shell. The SmartScreen web service also powers the Microsoft Defender Browser Protection extension for Chromium-derived browsers. While SmartScreen provides powerful controls to block attacks, the user remains in fullContinue reading “Enforcing SmartScreen with Policy”

Attack Techniques: SMS Gift Card Scams

Last week, I had the chance to fly to Redmond to meet my new teammates on the Protection team in Microsoft Defender. I also had the chance to catch up with a few old friends from the Edge team, one of whom I met for coffee on Friday morning. As we sat down with ourContinue reading “Attack Techniques: SMS Gift Card Scams”