Microsoft records rise in email phishing threats during third quarter of 2026

Microsoft Threat Intelligence reported that email-based phishing activity rose sharply at the end of the third quarter of 2026. The organization detected approximately 7.3 billion email-based phishing threats between July and September 2026. September alone saw nearly 3 billion threats detected, which represents a 41 percent increase from August. [1]

The report indicated that the overall rise in phishing activity did not apply equally to all delivery methods. QR code phishing activity remained far below the peak levels observed earlier in the year. Conversely, CAPTCHA-gated phishing reversed several months of decline, aided by the renewed use of SVG attachments. [1]

Microsoft also noted that malicious messages spoofing familiar business-service sender domains exposed risks associated with security overrides. Cyber threat intelligence focuses on collecting, analyzing, and sharing information about existing or potential cyber threats to help organizations predict and respond to attacks. [1][4]

Internet mail architecture relies on components such as Mail Transfer Agents, Message User Agents, and Mail Delivery Agents to relay and store messages. Attackers continue to target these communication channels, which served more than 4.6 billion users worldwide as of 2025. [5]