The Invisible Intrusion A completely mundane email, utterly devoid of malicious links or suspicious attachments, proved sufficient for the formidable TA488 hacker collective to secure persistent access to a victim's inbox. Consequently, the perpetrators only needed to wait patiently for the unsuspecting user to open the message within the Outlook web interface. Unveiling the Zero-Click Campaign On July 22, 2026, security analysts at Proofpoint officially uncovered this sophisticated new campaign.