ClickFix moves into the browser: Cryptocurrency theft with Google-hosted C2
Talos tracks a crypto-theft campaign abusing the Google Visualization API for C2, using browser-based ClickFix lures to inject web-skimmer JavaScript.
Criminal actors convinced targets to paste JavaScript into Chrome's address bar or install it in the Tampermonkey extension, injecting a web skimmer into sessions on two cryptocurrency trading websites; Tampermonkey also provides persistence. Since March 2026 the campaign retrieved obfuscated scripts via the Google Visualization API from public Google Sheets documents, hooking the fetch API and replacing cryptocurrency deposit addresses in responses and the clipboard. Lures pose as leaked reports of a nonexistent API flaw at cryptocurrency swap services and spread via Telegram, DarkForums, and paste sites since early October 2025. Talos warns the legitimate-service-abuse techniques could enable wider supply-chain attacks on e-commerce and customer-facing systems.
JSCeal Hides Crypto Malware in V8 Bytecode
Check Point details JSCeal, a crypto-stealing malware delivered as compiled V8 bytecode, and built a decompiler pipeline to expose its capabilities.
JSCeal, tracked by Check Point Research since early 2025, is a cryptocurrency stealer delivered as heavily obfuscated JavaScript compiled to V8 bytecode (.jsc) and run by a bundled Node.js runtime. Check Point, presenting at Black Hat USA 2026, extended the open-source View8 decompiler into a pipeline that recovered readable code from 23 samples, revealing theft of browser credentials and cookies, Telegram sessions, keystrokes, screenshots, HTTPS traffic interception with attacker-controlled certificates, and automated Google account takeover. Targeted overrides rewrite content for Binance, Bybit, and Ledger users. Later samples added AES-256-CBC encryption with externally supplied keys and expanded targeting to macOS.
Telegram Desktop Flaw Lets Hidden JavaScript Exfiltrate Messages From HTML Exports
Telegram Desktop HTML export XSS (CVSS 8.2) let bot messages exfiltrate exported chats; fixed in 7.0.1 but old exports stay vulnerable.
ExPatch researchers found that Telegram Desktop versions 4.15.1 (March 2024) through 6.9.3 wrote bot inline-keyboard button text into HTML chat exports without escaping, allowing a bot to plant invisible JavaScript. When a user opened the export in a browser, the script could exfiltrate every message in that 1,000-message file, rewrite the displayed content, or fake a verification form. The flaw (rated CVSS 3.1 8.2) was fixed by commit 8457d13a in 6.9.4 beta (July 3, 2026) and 7.0.1 stable (July 14, 2026), but pre-fix exports remain dangerous since updating the app does not fix old files. No CVE identifier or Telegram security advisory exists, and no exploitation in the wild is claimed.