The Computer Emergency Response Team of Ukraine (CERT-UA) has warned about targeted cyberattacks against employees in the defense-industrial complex and members of the Defense Forces of Ukraine, which have been ongoing since at least summer 2024 and have intensified recently. Attackers are using the Signal messenger app to distribute malicious files by compromising trusted contacts' accounts. In March 2025, CERT-UA observed that attackers were sending archived messages through Signal, which included a PDF and an executable file called DarkTortilla, designed to activate the DarkCrystal RAT (DCRAT) software. The focus of these deceptive messages has shifted to critical topics like unmanned aerial vehicles (UAVs) and electronic warfare equipment. CERT-UA has labeled this activity UAC-0200 and advises reporting any suspicious messages immediately. They have also compiled indicators related to the attacks, including specific file hashes, IP addresses, and URLs linked to the attackers' infrastructure.