ClickFix moves into the browser: Cryptocurrency theft with Google-hosted C2

• Cisco Talos is tracking a cryptocurrency-stealing campaign that abuses the Google Visualization API for command and control (C2), retrieving obfuscated JavaScript from a publicly published Google Sheets document and injecting it into the victim's browser session. 
• The actors use a variation on ClickFix social engineering. Instead of convincing targets to run commands against the operating system, they convince targets to paste JavaScript into the Chrome address bar or install it into the Tampermonkey browser extension, which also provides persistence. 
• The lure poses as a leaked vulnerability report describing a nonexistent API flaw at cryptocurrency swap services, and is aimed at users willing to exploit it for financial gain. Talos observed lures distributed through Telegram, DarkForums, and paste sites. 
• The injected script functions as a web skimmer. It hooks the browser's fetch API, replaces cryptocurrency deposit addresses in server responses and the user's clipboard, and displays counterfeit "bonus" interface elements. 

Cisco Talos has recently observed a criminal campaign that leveraged an interesting twist on what we refer to as “legitimate service abuse.” In this monthslong campaign, the criminal actors used the Google Visualization API as part of a scheme to inject malicious JavaScript into two cryptocurrency trading websites.