ZKsync Exploit Exposes $5M Vulnerability in Airdrop Contracts, Triggers 20% Token Plunge

Unauthorized Minting Drains 111M ZK Tokens Amid Admin Key Compromise

ZKsync’s token ecosystem suffered a major blow after a smart contract exploit linked to its airdrop distribution contracts enabled the unauthorized minting of 111 million ZK tokens, sparking a sharp selloff and renewed criticism over token contract security. The breach, confirmed by ZKsync on April 15, 2025, stemmed from a compromised admin key tied to three airdrop-related contracts, not the core protocol. 

The incident allowed the attacker to exploit a function called sweepUnclaimed() that remained unintentionally accessible in the deployed contracts. The team has since acknowledged this was never meant to be exposed, calling the exploit a critical misconfiguration rather than a flaw in the main network or governance infrastructure.

The attacker’s wallet, identified as 0xb1027ed67f89c9f588e097f70807163fec1005d3, quickly bridged approximately 1.7 million of the newly minted ZK tokens to Ethereum. That movement caused panic across exchanges, compounding the damage as prices tumbled by as much as 20%, down from $0.047 to under $0.04, within an hour. At peak valuation, the minted tokens were worth roughly $5 million.

On-chain data linked the exploit to a compromised address—0x842822c797049269A3c29464221995C56da5587D—used to manage permissions for the affected contracts. ZKsync emphasized that no user funds, protocol logic, governance mechanisms, or capped minters were impacted. “The incident is contained to the airdrop distribution contracts only,” the team stated, assuring that “no further exploits via this method are possible” as all mintable tokens under that vector had already been created.

The team has launched an active response effort in coordination with Seal 911, a crypto rescue alliance, and is working with centralized exchanges to track and potentially freeze the attacker’s assets. In a public message directed at the exploiter, ZKsync encouraged contact through a security inbox to discuss fund return and mitigate legal consequences. 

The platform’s quick transparency has helped prevent a deeper trust erosion, especially as recent events—including the OM token’s 90% crash from suspected internal sell-offs and the 20% plunge of Story Protocol’s IP token—have heightened scrutiny around token design and launch safeguards.

ZKsync has pledged a comprehensive post-mortem and acknowledged the oversight publicly, signaling a commitment to stronger standards for smart contract deployment in future token distributions. The breach revives long-standing industry concerns around residual vulnerabilities in airdrop contracts, admin key hygiene, and the broader implications of token drops that remain claimable long after launch.

This article has been refined and enhanced by ChatGPT.