Cisco Talos Incident Response (Talos IR) has observed the ongoing use of legitimate digital document publishing (DDP) sites for phishing, credential theft and session token theft during recent incident response and threat intelligence engagements. Hosting phishing lures on DDP sites increases the likelihood of a successful phishing attack, since these sites often have a favorable reputation, are unlikely to appear on web filter blocklists, and may instill a false sense of security in users who recognize them as familiar or legitimate. DDP sites allow adversaries to quickly deploy and decommission malicious documents on a single platform. Talos IR also observed an adversary move between DDP sites within a short period. Talos IR has responded to several recent incidents in which threat actors used legitimate digital document publishing sites such as Publuu and Marq to host phishing documents as part of ongoing credential and session harvesting attacks. Threat actors have used a similar tactic of deploying phishing lures on well-known cloud storage and contract management sites such as Google Drive, OneDrive, SharePoint, DocuSign and Oneflow. However, DDP sites could represent a blind spot for defenders, because they are unfamiliar to trained users and unlikely to be flagged by email and web content filtering controls. Recent malicious activity observed across these platforms underscores the need for security teams to ensure that phishing protections and user awareness…Read More