Phantom Extension

KREMLIN Banking Malware Hijacks Chrome and Edge to Steal Credentials and Session Tokens in Brazil

Elastic Security Labs researchers have detailed the operations of the KREMLIN banking malware, tracked under the identifier REF9334, which targets Chrome and Edge browsers to harvest credentials and session tokens. The campaign focuses almost exclusively on Brazil, with 98 percent of the 1,515 identified infections located in the country and impersonating a dozen Brazilian banks. Infection begins with multi-stage JavaScript loaders disguised as banking documents, invoices, or corporate papers that require manual execution by the victim. The loaders then deploy C++ installers and malicious browser extensions that modify the Secure Preferences file, enable developer mode, and overwrite protection objects with forged metadata using a technique called Phantom Extension. Once active, the extension collects session tokens, cookies, sessionStorage and localStorage data, 15 days of browsing history, screenshots, open tab information, and full HTML of visited pages. The operation has run since May 2025 across seven distinct campaigns and began using Ethereum smart contracts for infrastructure on 19 May 2026.