Hackers Exploit FortiGate SSL-VPN Flaw to Breach Thai ISP and Deploy MeshCentral Backdoor
Threat actors exploited FortiOS SSL-VPN flaw CVE-2024-21762 to breach Thai ISP Triple T Broadband, gaining root-level persistence via MeshCentral agents.
Attackers exploited CVE-2024-21762, an out-of-bounds write enabling unauthenticated RCE in FortiOS SSL-VPN, against Triple T Broadband's FortiGate 60F at mail.3bb.co.th, launching a Node.js reverse shell via a ROP payload. Hunt.io uncovered the operation through an exposed staging directory at 92.63.180[.]133:8888 containing 298 files of exploits, credential-harvesting scripts, session cookies, and a device inventory. Post-compromise, the actors deployed MeshCentral agents (device group TH-3BB, C2 www.ayuthayatech.com) running as root, plus a hidden SUID backdoor at /usr/local/bin/.rc, and also targeted an internal Pentaho/Tomcat server with Ghostcat (CVE-2020-1938). A cleanup script removed logs, shell histories, and web shells while deliberately preserving the MeshCentral agent and SUID backdoor.
Hackers Actively Exploiting FortiGate Firewalls to Deploy Custom Node.js Malware
Attackers actively exploit CVE-2025-25249 in FortiGate firewalls to deploy PivotC2, a Node.js RAT that decrypts VPN and admin credentials.
SOCRadar assesses with high confidence that threat actors are actively exploiting CVE-2025-25249, a CVSS 9.8 heap buffer overflow in the cw_acd daemon (CAPWAP, UDP 5246) affecting FortiOS 6.4-7.6.3 and FortiSwitchManager 7.0.x/7.2.x. Attackers deploy fortirun.bin and PivotC2, a Node.js post-exploitation framework that harvests configurations and decrypts SSL-VPN, wireless, and admin credentials using AES-256-CBC and AES-128-GCM. Over 30,000 FortiGate IPs were scanned and 178 devices compromised, including two confirmed full intrusions of US organizations with Exchange mailbox exfiltration to Wasabi storage. STRU attributes the campaign to a Russian-speaking, financially motivated cybercrime operator.
CVE-2025-25249 Exploitation Delivers PivotC2, a FortiGate Post-Exploitation RAT
Attackers exploiting CVE-2025-25249 in Fortinet FortiGate firewalls deploy PivotC2, a post-exploitation RAT, on exposed edge devices.
SOCRadar reports that exploitation of CVE-2025-25249 is being used to deploy PivotC2, a purpose-built post-exploitation RAT, on FortiGate firewall appliances. The attack follows the common pattern of compromising public-facing edge devices such as VPNs, routers, and firewalls as the initial entry point. Defenders running FortiGate appliances should prioritize patching and watch for post-exploitation activity indicating RAT deployment.