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.
Weekly Cybersecurity Newsletter Bulletin – Microsoft 0-day, FortiOS, PAN-OS Flaw, Revolut Data Breach, and 20+ Stories
Weekly roundup: Microsoft patches 973 flaws including two actively exploited zero-days; FortiOS CAPWAP flaw deploys PivotC2 RAT; PAN-OS root RCE disclosed.
Microsoft's September 2026 Patch Tuesday fixed 973 vulnerabilities, including two zero-days under active exploitation: CVE-2026-85880 (Windows ALPC) and CVE-2026-81963 (Windows Update Stack), both elevation-of-privilege bugs. SOCRadar reported active exploitation of CVE-2025-25249 (CVSS 9.8) in FortiOS CAPWAP, deploying a Node.js RAT called PivotC2 that exfiltrates Exchange mailboxes to Wasabi cloud storage; 178 devices were compromised out of 30,000 scanned IPs, attributed to a Russian-speaking financially motivated group. Palo Alto disclosed CVE-2026-0310, a 9.2-rated buffer overflow enabling root code execution on PA-Series firewalls, and Fortinet disclosed CVE-2026-84393, a ZTNA certificate validation MITM flaw. Cyera also revealed CVE-2026-6471 ('PostGREShell'), a 12-year-old PostgreSQL logical-decoding flaw allowing code execution via REPLICATION-privileged accounts.
Thai Broadband Provider Hacked via Fortinet Vulnerability
Hackers exploited Fortinet CVE-2024-21762 RCE to breach Thai broadband provider 3BB, deploying MeshCentral backdoors and credential-harvesting tools across its network.
Hunt.io uncovered an intrusion staging directory in Thailand containing 298 files of custom tooling built for Triple T Broadband (3BB) and its former owner Jasmine. Initial access came via fingerprinting a FortiGate SSL-VPN appliance and exploiting CVE-2024-21762 for remote code execution, after probing CVE-2018-13379, CVE-2022-42475, and CVE-2023-27997. The actor also probed F5 BIG-IP for CVE-2021-22986, CVE-2022-1388, and CVE-2023-46747, escalated privileges with PwnKit and Dirty COW, used MeshCentral as a C2 backdoor, harvested SSH/database/SNMP/Radius credentials, deployed PHP web shells, and ran cleanup scripts to hide the intrusion.
Gunra Ransomware Exploits Fortinet FortiOS, FortiProxy Flaws to Breach Networks
CISA, FBI, and South Korean agencies warn Gunra ransomware, with 51 victims since April 2025, exploits Fortinet flaws for double-extortion attacks on critical infrastructure.
CISA, the FBI, and South Korean agencies warned of Gunra ransomware attacks targeting healthcare, financial services, government, and professional services worldwide. The Conti-derived operation exploits internet-facing Fortinet FortiOS and FortiProxy flaws CVE-2024-55591 and CVE-2025-24472 for initial access, then deploys double extortion with Salsa20/ChaCha20 encryption and publishes non-payers on a leak site within five to seven days. Ransomware.Live lists 51 victims since April 2025, mostly in South Korea, Brazil, Spain, Thailand, and Hong Kong. The group uses Impacket tools for SMB lateral movement and NTDS credential dumping, tampers with VDI authentication to accept a designated OTP value to bypass MFA, and launched a RaaS affiliate program in January 2026 under the new alias Golden Community.