Sekoia’s TDR team uncovered spear-phishing campaigns by the Russian-linked group Calisto in May-June 2025, targeting Reporters Without Borders and others. Calisto, associated with Russian intelligence, focused on organizations linked to Ukraine and the West. Their phishing tactics involved fake trusted contacts, missing attachments, or non-working files to trick victims into requesting follow-up documents containing malicious links or decoy PDFs. The phishing kits employed advanced techniques like Adversary-in-the-Middle, intercepting credentials, and 2FA. Calisto’s campaigns make extensive use of compromised websites, redirectors, and numerous custom domains for phishing and credential harvesting. NGOs aiding Ukraine and associated researchers remain high-risk targets.
https://blog.sekoia.io/ngo-reporters-without-borders-targeted-by-calisto-in-recent-campaign/