Large-Scale Theft of Ethereum Dormant Wallets Breaks 7-Year Silence; Past Security Flaws Identified as Cause

Hundreds of Ethereum wallets that had remained silent for seven years were suddenly activated this week. However, it was revealed that this was not the intention of the wallet owners, but rather a phenomenon occurring as assets were being entirely emptied by an organized attack. This incident is reigniting fears regarding the security of early cryptocurrency storage methods.

Starting April 30, 2026, hundreds of wallets that have been dormant for over seven years on the Ethereum mainnet are being emptied. This appears to be an organized theft of private keys rather than a mere coincidence.

On-chain investigator WazzCrypto first alerted the public to the attack on Ethereum mainnet wallets via their X (formerly Twitter) account on April 30, 2026. Most of these wallets had not seen any transactions since around 2019, and the attacker concentrated the funds into a single address with a specific tag.

Scale of the Massive Theft and Money Laundering Routes

It has been identified that more than 500 wallets were affected by this attack. The stolen assets amount to approximately 261 ETH, estimated to be worth between $590,000 and $800,000 at current values. While there were initially conflicting reports regarding the scale of the loss, the vast number of affected accounts caused a significant shock to the market.

• Incident Period: April 30 – May 1, 2026
• Number of Affected Wallets: 500+
• Dormancy Period: 7+ years (No activity since before 2019)
• Stolen Asset Volume: Approx. 261 ETH
• Primary Protocols Used: THORChain, Uniswap

The attackers utilized sophisticated on-chain routes to make the stolen funds difficult to track. They obscured the source of the funds by moving the stolen Ethereum through decentralized protocols such as THORChain and Uniswap. This is interpreted as a typical tactic to evade tracking by security authorities and to cash out the assets.

In particular, the act of mixing assets through decentralized exchanges is intended to confuse investigative efforts by moving funds far away from the initial point of theft. The attackers prioritized speed in moving the funds, suggesting the work of highly trained hackers aiming to secure large-scale assets safely in a short period.

A Time Bomb Left by Past Security Vulnerabilities

Experts believe this incident did not exploit a new vulnerability within the Ethereum network itself. Instead, the prevailing analysis is that it likely stems from security management negligence by early wallet services used in the mid-2010s. It is known that some services at the time stored or transmitted private keys in insecure ways.

If the attackers had obtained a database of leaked private keys from the past, it would have been difficult for wallet owners to avoid being victimized, regardless of how cautious they were. This demonstrates that security mistakes from years ago are acting like a 'time bomb' for current asset holders. This incident goes beyond a simple hack, proving how past 'security debt' can impact the current market.

This incident has dealt a significant psychological blow to long-term holders. As dormant wallets believed to be safe were attacked, anxiety spread throughout the market. This threat is of a completely different nature than whales from the ICO era voluntarily moving funds, suggesting that long-term investors need to re-examine their asset management strategies.

Security Lessons and Future Precautions

This incident serves as a strong warning to users holding assets in accounts created through old wallet services. Experts recommend migrating assets from past wallets with potential leak risks to hardware wallets that apply new security standards. It is important to remember that online wallet services used in the past may no longer be secure.

Investigations into the specific source of the leak are currently ongoing. To prevent further damage, efforts are needed to continuously monitor on-chain activity and re-examine the usage history of early platforms whose security has not been verified. ND MAGAZINE will continue to track the results of the follow-up investigation and additional cases of damage.