Why 'Call This Number' TOAD Emails Beat Gateways

Researchers analyzed roughly 5,000 email detections that bypassed secure email gateways and identified telephone-oriented attack delivery (TOAD) — phishing emails containing only a phone number — as a prominent evasion technique (about 28% of bypasses). The report details how TOAD and multilayered evasion combinations (QR codes, calendar/sharepoint delivery, multi-hop URLs, sender spoofing) defeat typical email defenses across Google and Microsoft platforms, notes scalability and low cost for attackers, and provides detection and user-training recommendations to mitigate the risk.