PsExec

Qilin Ransomware Operators Exploit Palo Alto PAN-OS VPN Flaw CVE-2026-0257

Operators linked to the Qilin ransomware group have been actively exploiting an authentication bypass vulnerability in Palo Alto Networks PAN-OS to gain initial access to corporate networks. The attacks, observed in June 2026, targeted the GlobalProtect VPN service running on Palo Alto firewalls and were tracked under CVE-2026-0257. Attackers used specially crafted authentication cookies to establish unauthorized VPN sessions, after which they harvested credentials from Windows LSASS processes and Active Directory NTDS databases. Lateral movement relied heavily on PsExec and administrative shares, supplemented by tools such as AnyDesk, Ngrok, LogMeIn, and NetExec. Before deploying the ransomware binary stored as win.exe in C:\PerfLogs\, the threat actors disabled Microsoft Defender real-time protection and cleared event logs. The vulnerability affects PAN-OS versions 10.2, 11.1, 11.2, and 12.1 as well as certain Prisma Access editions, while Panorama and Cloud NGFW remain unaffected.