Fake Polymarket Bot Delivers Infostealer to 53 Developers

A fake trading bot for Polymarket's prediction markets turned into a credential-stealing operation. The GitHub repository, Trum3it/polymarket-arbitrage-bot, promised annual profits above $80,000. Instead, it delivered an infostealer that targets crypto wallet keys, browser passwords, and cloud credentials.

Security firm SlowMist flagged the repository on July 1. SafeDep later identified 30 malicious npm packages spread across several accounts, all tied to the same fake bot. At least 53 developers cloned the repo and ran the installation command before the scam was exposed, SafeDep said.

The attackers knew their audience. Real Polymarket bots have made eye-popping returns. One bot profiled by analyst Dexter's Lab turned $313 into $414,000 in a month. Another, tracked by researcher Igor Mikerin, generated $2.2 million over two months. That track record gave the fake bot credibility.

The instructions asked users to paste their Polymarket private key into a .env file and run "npm install." During installation, a hidden dependency called clob-client-math executed the malware. The repository's package.json listed four dependencies. Three were legitimate: the official Polymarket SDK, ethers, and dotenv. The fourth, clob-client-math, was never imported anywhere in the bot's source code. That mismatch is the tell, SafeDep said.

What the malware takes

The infostealer scrapes crypto wallet vaults from eight major wallets including MetaMask and Phantom. It grabs browser cookies and saved passwords, SSH keys, AWS credentials, npm and PyPI tokens, Docker configs, shell history, and password manager databases from Bitwarden, KeePass, and 1Password. Any developer who ran "npm install" on that repo should treat the machine as compromised, SafeDep warned.

Who is behind it