Description

Between late 2024 and early 2025, Darktrace’s Security Operations Center (SOC) identified a surge in phishing campaigns exploiting legitimate SaaS platforms like Milanote. Threat actors used Milanote’s trusted infrastructure to send phishing emails that bypassed security filters and appeared credible. These messages, often using subject lines like “new agreements” and referencing internal colleagues, enticed users into clicking malicious links hosted on Milanote, leading to credential harvesting sites. These attacks incorporated the Tycoon 2FA phishing kit, a tool first detected in August 2023 and distributed via Phishing-as-a-Service (PhaaS) models. It enables Adversary-in-the-Middle (AiTM) attacks that intercept login credentials and multi-factor authentication (MFA) tokens on counterfeit Microsoft and Google login pages. Once MFA is completed, Tycoon captures session cookies, allowing attackers to hijack sessions—even if passwords are reset. Darktrace analysis showed that users who clicked Milanote links subsequently contacted Tycoon-related domains such as lrn.ialeahed[.]com. Attackers then accessed compromised SaaS accounts from unusual U.S.-based IPs masked by VPNs like Hide My Ass. Meanwhile, legitimate users remained active elsewhere, illustrating the stealthy nature of AiTM techniques. Post-compromise, threat actors often set up mailbox rules—such as those deleting emails containing “milanote”—to evade detection. Compromised accounts were also used to propagate further phishing, often through multilingual emails. Darktrace’s AI-driven detection flagged suspicious sender behavior, rare login patterns, and sudden increases in email recipients, assigning an 82% probability of phishing. In response, Autonomous Response mechanisms disabled affected accounts and terminated sessions within minutes, while SOC teams assisted in remediation and cleanup. This campaign demonstrates the growing sophistication of phishing operations using legitimate platforms and AiTM techniques. As MFA becomes standard, attackers increasingly rely on advanced kits like Tycoon 2FA, highlighting the need for adaptive defenses and user vigilance to safeguard SaaS environments.