A newly discovered campaign dubbed GreedyBear has leveraged over 150 malicious extensions to the Firefox marketplace that are designed to impersonate popular cryptocurrency wallets and steal more than $1 million in digital assets. The published browser add-ons masquerade as MetaMask, TronLink, Exodus, and Rabby Wallet, among others, Koi Security researcher Tuval Admoni said. What makes the activity notable is the threat actor's use of a technique that the cybersecurity company called Extension Hollowing to bypass safeguards put in place by Mozilla and exploit user trust. It's worth noting that some aspects of the campaign were first documented by security researcher Lukasz Olejnik last week. "Rather than trying to sneak malicious extensions past initial reviews, they build…