EtherHiding

EtherHiding Campaign Hides Banking Trojan C2 in Polygon Smart Contracts

Security researchers have detailed the EtherHiding campaign, which conceals command-and-control infrastructure inside smart contracts on the Polygon blockchain. The final payload is a malicious browser extension that functions as a banking trojan, intercepting credentials and two-factor codes from approximately 479 financial and cryptocurrency websites. Instead of embedding fixed addresses in its code, the malware queries an encrypted C2 server address from the smart contract, allowing operators to change destinations through low-cost blockchain transactions that bypass domain blocking. Infection begins when victims visit one of 31 compromised legitimate sites that inject JavaScript displaying a fake CAPTCHA prompt. The prompt instructs users to press Windows+R and execute a PowerShell command, a social engineering technique known as ClickFix that downloads the malicious scripts without exploiting any software vulnerability. The campaign has remained active from November 2025 through at least September 2026, demonstrating the resilience of blockchain-based infrastructure against traditional takedown methods.