KREMLIN Banking Malware Infects Over 1,500 Systems With Malicious Chrome Extension
Elastic tracks KREMLIN banking malware that used fake Brazilian bank JavaScript lures to deploy malicious Chrome and Edge extensions on 1,515 systems.
Elastic researchers tracked the KREMLIN banking malware operation across seven campaigns over 15 months, infecting 1,515 systems, 98.75% of them in Brazil. Portuguese-language lures posing as bank records and invoices deploy a hostile 'AVSync' extension into Chrome and Edge profiles that harvests passwords, session cookies, keystrokes and screenshots. Loaders check for sandboxes, create scheduled tasks and fetch fresh infrastructure from an Ethereum smart contract; a network canary takeover temporarily disrupted infections.
The extension you never installed: KREMLIN forges Chrome's own integrity checks to steal banking sessions
Elastic details KREMLIN, a Brazilian banking malware whose malicious Chrome/Edge extension forges Chromium integrity checks to steal sessions.
Elastic Security Labs tracked operation REF9334 and its KREMLIN toolkit, a Brazilian banking malware campaign impersonating twelve banks across seven campaigns since May 2025. The infection chain uses multi-stage obfuscated JavaScript loaders with sandbox checks (file and process counting), scheduled-task persistence, and an Ethereum smart contract acting as a dead-drop resolver for C2 and payload URLs, abusing Archive.org for hosting. The malicious browser extension bypasses Chromium integrity mechanisms by manipulating Secure Preferences and regenerating required HMACs and App-Bound encrypted hashes. Threat Command disrupted over 1,500 infections by registering the kill-switch canary domain.
Malicious Twitch Extension Exposes OAuth Tokens of 30,000 Chrome and Firefox Users
Malicious 'Twitch Enhanced Viewer | JeetBot' browser extension stole live OAuth session tokens from roughly 31,000 Chrome and Firefox users.
Socket.dev found the cross-store extension 'Twitch Enhanced Viewer | JeetBot' rerouted Twitch playlist requests through operator-controlled proxies, attaching the victim's account-level OAuth token as a URL parameter where it could be logged in cleartext. About 30,000 Chrome and 552 Firefox installs were exposed, with tokens forwarded for nearly every watched channel to infrastructure tied to a Russian commercial bot service. The stolen bearer token enables chat, whisper, account-setting access and channel-point spending without the password or 2FA.
19 Chrome and Edge Extensions Found With Wallet-Stealing and Crypto
Socket found 19 malicious Chrome and Edge extensions, active since February 2024, stealing wallet seed phrases and credentials and draining crypto from about 80,000 users.
Socket researcher Karlo Zanki documented a cluster of 18 Chrome and one Edge extensions with wallet secret stealing and cryptocurrency draining capabilities, tracked as campaign Superior and possibly active since February 2024. The actor created 14 extensions and bought five legitimate ones, later pushing malicious updates; the largest, Enable Right Click & Copy, has roughly 80,000 installs across both browsers. The extensions maintain WebSocket C2 connections with endpoint rotation, strip CSP headers, and load 16 modules including multi-chain wallet drainers, hardware-wallet seed-phrase harvesters, credential grabbers, and ClickFix-style lures.
Open VSX Removes 77 Malicious Evil Twin Extensions Exfiltrating Developer Data
77 malicious 'evil twin' Open VSX extensions impersonated developer tools and exfiltrated hostnames and detailed workspace reconnaissance to mangorbit.com.
Manifold Security found 77 extensions uploaded to the Open VSX marketplace between July 26 and August 1, 2026 that impersonate real Microsoft VS Code Marketplace tools, with all 77 sending data to mangorbit.com. 58 lightweight variants exfiltrate the hostname, while 19 recon variants collect editor details, OS username, Git remote hosts, CI environment variables (GitHub, GitLab, Azure DevOps, Buildkite, CircleCI, Codespaces, Gitpod), and installed extension IDs. The recon variant retries for up to seven days and can fall back to a DNS TXT record for exfiltration if the primary domain is blocked. The extensions were removed from Open VSX by August 3, 2026; the disclosure follows a separate npm supply chain campaign, ChainDrop, which compromised 450 packages with a Shai-Hulud worm variant.
737 Chrome VPN Extensions Caught Routing Traffic Through Proxies. Check If You Have One
Researchers found 737 Chrome VPN extensions, many impersonating brands like NordVPN, routing roughly 75,000 users' browser traffic through attacker-controlled SOCKS5 proxies.
Socket and researcher Kush Pandya identified 737 Chrome VPN and proxy extensions, published across at least 40 developer accounts with 75,486 installs, that route entire browser sessions through one provider's SOCKS5 proxies on port 1082. Of these, 274 impersonate 66 established brands including Proton VPN, NordVPN, Surfshark, ExpressVPN, and Cloudflare 1.1.1.1. The proxy bypass list only excludes loopback addresses, exposing visited destinations, source IPs, TLS SNI values, and plain-HTTP request bodies to the operator. 221 extensions have been removed from the Chrome Web Store while 516 remain listed as active.
40 Malicious Firefox Extensions Pose as Web3 Products to Steal Wallet Secrets
Socket found 40 malicious Firefox extensions impersonating OKX, Rabby Wallet, and TronLink to steal cryptocurrency wallet recovery phrases and private keys.
The Socket Threat Research team identified 40 malicious Firefox extensions masquerading as Web3 products including OKX, Rabby Wallet, and TronLink, part of a broader set of 77 add-ons sharing source code and infrastructure overlaps. The campaign, dubbed Offside Wallet Theft Factory, has been active since March 2026 and remains unattributed. Of the 40 confirmed malicious extensions, 15 capture recovery phrases and private keys exfiltrated through Cloudflare Workers, 13 modified Rabby Wallet builds exfiltrate serialized keyrings before local encryption, seven use attacker-controlled Supabase projects as remote switches, and five capture credentials and clipboard data via hard-coded C2. Some extensions began as sports score or utility shells before being repurposed into wallet stealers under the same Firefox ID.