European stablecoin issuer StablR has suspended minting and redemption services for its USDR and EURR tokens after a cyberattack left the assets undercollateralized, according to a company statement.
Onchain investigator ZachXBT publicly reported the exploit over the weekend, posting that two contracts linked to StablR’s USDR and EURR stablecoins appeared compromised.
The Malta-based company said it detected “irregularities” in its systems after internal alerts triggered an investigation.
StablR has frozen token operations and asked exchanges to stop trading, deposits and withdrawals for both stablecoins while the company investigates the breach. USDR currently has a market cap of $20 million, while EURR has a market cap of $10 million, according to CoinGecko data.
StablR acknowledged that the circulating supply of USDR and EURR is “currently not fully collateralized at the 1:1 ratio,” as required by the European Union’s Markets in Crypto-Asset (MiCA) Regulation.
The company announced its intention to notify Malta’s financial regulator, the Malta Financial Services Authority, under the EU Digital Operational Resilience Act and MiCA reporting rules. External cybersecurity companies and law enforcement agencies are also involved.
Blockchain security company GoPlus Security said the attack could have come from a weakness in the configuration of StablR’s Ethereum multisignature wallet.
The minting wallet was configured with a multisignature threshold of 1 of 3, according to GoPlus. Any of the three authorized owners could approve transactions on their own.
Researchers say the attackers compromised a single key, added themselves as an administrator, and removed legitimate signers. They then minted approximately 8.35 million USDR and 4.5 million EURR, or approximately $13.5 million in uncollateralized tokens at the peg level.
The low liquidity of decentralized exchanges means that the attackers made around $2.8 million after offloading the freshly created supply.
StablR’s tokens briefly lost up to 50% of their peg before starting to recover. USDR is now at $0.994, while EURR is at $0.548, well below the current value of the Euro, which is $1.16.
Chief executive Gijs op de Weegh said the company was acting “with complete transparency” as the investigation continues.
