GreedyBear Scam Group Escalates Industrial-Scale Crypto Theft with Sophisticated Tactics

A cybercrime syndicate known as “GreedyBear” has propelled cryptocurrency theft to an unprecedented level, stealing over $1 million from unsuspecting users through a complex web of fake wallet browser extensions, malware strains, and deceptive scam websites. Security researchers warn this represents a new era of large-scale, diversified crypto attacks, with GreedyBear leveraging advanced techniques to target digital asset holders worldwide.

GreedyBear’s Multi-Pronged Crypto Theft Tactics

According to cybersecurity firm Koi Security, GreedyBear stands apart by executing an industrial-scale operation that combines methods typically used by separate criminal factions. Instead of focusing solely on browser-based threats, ransomware, or phishing sites, GreedyBear has expertly deployed all three categories in parallel greatly amplifying both reach and impact.

“Most groups pick a lane… GreedyBear said, ‘Why not all three?’ And it worked. Spectacularly,” said Koi Security researcher Tuval Admoni.

1. Fake Crypto Wallet Extensions Flood Browser Marketplaces

Over $1 million in losses have been traced to more than 650 malicious tools many of which are browser extensions designed to impersonate popular crypto wallets like MetaMask, TronLink, Exodus, and Rabby Wallet. GreedyBear has published 150+ fraudulent extensions to platforms like the Firefox marketplace.

Using a technique called “Extension Hollowing,” the group initially releases a legitimate-looking product to pass store security checks. After gaining users and positive reviews, the extension is secretly updated with credential-stealing malware. These fake wallet extensions are capable of intercepting wallet recovery phrases and passwords as soon as users enter them.

“This campaign shows how cybercriminals are weaponizing browser extension store trust cloning popular plugins and later injecting credential-stealing malware,” noted Cyvers CEO Deddy Lavid.

2. Crypto-Stealing Malware Distributed via Russian Websites

Koi Security’s research uncovered nearly 500 samples of malware aimed directly at crypto users. Variants like LummaStealer and Luca Stealer are distributed through shady Russian sites offering pirated or cracked software, infecting victims’ devices and capturing sensitive wallet data. Some malware strains even lock files and demand crypto payments as ransom.

3. Network of Sophisticated Scam Crypto Websites

GreedyBear’s third attack arm consists of polished fake websites advertising crypto wallets, hardware devices, and wallet repair services. Unlike obvious phishing attempts, these sites feature slick landing pages, giving victims a false sense of trust. Many are run from a centralized server acting as a command-and-control hub, streamlining credential harvesting and ransomware delivery.

AI-Powered, Rapidly Evolving Attacks

Security experts note that GreedyBear appears to be using AI-generated code, allowing it to quickly diversify attack types, cycle through targets, and make its scripts harder to detect. The campaign’s scale and adaptability signal a new normal in crypto cybercrime: “It’s no longer a passing trend it’s the new normal,” Admoni stressed.

Key Takeaways: How Crypto Users Can Protect Themselves

• Be Skeptical of Browser Extensions: Download crypto wallet extensions only from verified sources and official sites. Check developer credentials and reviews carefully.
• Avoid Suspicious Downloads: Never install software from unofficial or pirated sources, as these are common vectors for crypto-targeting malware.
• Double-Check Website URLs: Visit only the official webpages of crypto projects and avoid clicking on ads or unknown links claiming to offer wallet or recovery services.
• Routine Security Audits: Regularly review and cleanse browser extensions, run anti-malware scans, and consider using hardware wallets for significant crypto holdings.
• Stay Informed: Follow updates from reputable security firms on the latest scam trends and vulnerabilities in the crypto space.

Why This Matters for Crypto Security

The GreedyBear campaign’s success highlights urgent gaps in browser extension vetting, the sophistication of new attack chains, and the heightened need for both user vigilance and improved industry security standards. As AI-powered scams become the new norm, security experts urge browser vendors to enforce stricter approval processes and promote developer transparency.

Crypto holders should remain cautious and proactive regularly vetting tools, staying up-to-date on threats, and embracing secure wallet practices to safeguard assets against next-generation crypto crime.