Inside Knight Office, a New M365 AiTM Phishing Kit
Huntress details Knight Office, a new AiTM phishing kit stealing Microsoft 365 session tokens and registering attacker-controlled devices.
Huntress investigated an August 18, 2026 adversary-in-the-middle attack using the Knight Office phishing kit, which captured Microsoft 365 session tokens via a DocuSign-style lure routed through a Monday.com tracking link and a compromised Joomla site. After token capture, the actor enrolled an unauthorized host in Microsoft Entra ID and bound a Windows Hello for Business key credential to the account. The kit's operator console, found at IP 104.37.188.94, is built on Python Flask and hosts at least 25 .vu phishing domains. Telemetry links the kit to at least nine token-replay logins in two weeks and roughly 700 reported lure emails since April.
Phishing Attacks Serve Browser-in-the-Browser Pages, Rogue RMM Persistence
Phishing emails with browser-in-the-browser fake Adobe pages trick users into installing rogue ScreenConnect clients granting persistent remote access.
Huntress SOC investigated two August incidents where phishing links led to fake CAPTCHA checks and Adobe PDF Reader lures rendered as browser-in-the-browser (BiTB) pages spoofing legitimate domains like get.adobe.com. Victims downloaded what they believed was Acrobat Reader but actually installed ScreenConnect.ClientSetup.exe from attacker infrastructure, yielding two rogue ScreenConnect clients with service-based persistence. The attacker used cmd.exe and curl to stage a second client connecting to 144.172.115.59, leveraged a ScreenConnect Trial Relay domain for stealth, and ran HideCursor.exe as a defense-evasion binary. Incident 2 arrived via AT&T Office@Hand (RingCentral), with both chains stopped before broader impact.
ASCII smuggling crosses over from AI prompt injection to phishing evasion
Microsoft details high-volume phishing campaign using ASCII smuggling (Unicode tag chars) for filter evasion, peaking at 2.3M messages.
Microsoft researchers observed a high-volume finance-themed phishing campaign using invisible Unicode tag characters (U+E0000–U+E007F), a technique known from AI prompt injection research as ASCII smuggling, to split lure words like 'funding' and evade email filters. Telemetry from Microsoft Defender for Office 365 showed signature hits jump from roughly 21,000 messages on February 8, 2026 to more than 1.3 million on February 9, peaking above 2.3 million on February 11, with elevated weekday activity lasting approximately three months. The discovery emerged from prompt injection protection research, showing AI-era evasion techniques crossing into traditional phishing. Most messages were flagged by layered Defender protections rather than a single Unicode-specific signal.
New Phishing Attack Uses Blob URLs to Hide Malicious Pages From Security Scanners
Barracuda detailed a DocuSign-themed phishing campaign that renders credential-harvesting pages as browser blob URLs, evading URL reputation and blocklist defenses.
Barracuda researchers report a credential-harvesting phishing campaign that starts with a DocuSign-themed email containing a calendar invitation and routes victims through legitimate Microsoft OAuth endpoints and Microsoft Teams. A crafted redirect parameter leads Teams to load external content from cdn.bloom[.]io, which the browser renders as a blob URL — a session-only address held in local memory with no persistent public URL to crawl, categorize, or blocklist. The locally generated page registers a service worker, runs inside a sandboxed iframe, and is dynamically steered by backend infrastructure, indicating a centrally managed phishing platform. Barracuda recommends phishing-resistant MFA such as FIDO2 keys and passkeys, monitoring OAuth flows and redirect chains, and Teams malicious URL protection.
Hackers Use Blob URLs and Microsoft Teams to Create Phishing Pages Inside Victims’ Browsers
Barracuda details a phishing campaign using Microsoft Teams OAuth redirects and browser blob URLs to render local fake DocuSign login pages for credential theft.
Barracuda researchers identified an active phishing campaign that routes DocuSign-themed emails with calendar invites through a Microsoft OAuth endpoint and crafted redirects into Microsoft Teams, then renders a fake sign-in page via a browser-generated blob URL. Because the page is assembled locally in memory and can register service workers and run in a sandboxed iframe, URL-reputation checks largely see legitimate Microsoft domains. The goal is credential theft and account takeover, not a flaw in Teams itself.