Blockchain security firm Scam Sniffer has issued an urgent warning about a dramatic surge in signature phishing attacks, with January 2026 losses reaching $6.27 million across 4,700 drained wallets. This represents a staggering 207% increase from December 2025, marking a sharp reversal in the broader downward trend of crypto phishing incidents.

While overall phishing losses declined 83% in 2025 compared to 2024, January's spike highlights how attackers are evolving their tactics. Signature phishing exploits users' trust by prompting them to sign seemingly harmless off-chain messages that actually authorize unlimited token spending or NFT transfers. The attacks are particularly insidious because the initial requests appear legitimate, such as approving token deposits or NFT listings.

Two wallets alone accounted for approximately 65% of January's total losses, including $3.02 million stolen through permit and increaseAllowance attacks targeting SLV and XAUt tokens. Security experts note that Ethereum's Fusaka upgrade, which dramatically reduced transaction fees, has made mass address poisoning campaigns economically viable for attackers. The lower costs allow criminals to send millions of dust transactions, hoping for a small number of high-value mistakes from unsuspecting users.