Yeld Finance "Lightning Loan" Attack

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Yeld Finance

According to the SlowMist story, there was a lightning attack here. The Blockcast.cc story raised doubts about the nature of the attack, and there was limited coverage by any other security experts.

The original post about the attack was deleted by the team. According to SlowMist, the funds were returned by the attacker. The Solidity Finance audit notes that the project team has notable power in the ecosystem.

This is a global/international case not involving a specific country.

About Yeld Finance

"Yeld Finance is a DeFi protocol pushing blockchain technology forward with innovative developments in the lending, staking and NFT spaces among others." "YELD is a deflationary decentralized finance (DeFi) protocol built on Ethereum. The YELD platform allows users to earn by staking their stablecoins in our smart contract vaults and earn YELD tokens in return." "Yeld finance in a few words is the next step in stablecoin yield farming for those that want high and consistent returns for the long term, to reward holders permanently."

"Our staking dApp uses a new Buy and Burn algorithm where we split the daily yield generated by users in half to automatically buy ETH and exchange it for YELD tokens on Uniswap. Those YELD tokens are burned to reduce the total supply resulting in an instant price increase. The total supply of YELD will continue to decrease until it reaches 10,000 YELD."

"On February 27, 2021, Beijing time, [Beosin-Blockchain Security Situational Awareness Platform (Beosin-OSINT)] Public opinion monitored that Yeld.finance, a well-known DeFi project, officially issued a notice stating that the project’s DAI pool suffered lightning Loan attack."

"The Beosin security team immediately intervened in response to the transaction mentioned in the original text (0x57b378f8d20d3945ab40cd62aa24063f375bcfc5693c2e788dc193ffa1a5cc3a) for analysis. The analysis after the discovery, the transaction is Yeld.finance project’s own policy mechanism resulting from the transfer of funds, regardless of the credit lightning attack. The lightning loan attack means not to bear the pot."

"The DAI pool of Yeld.finance, the DeFi revenue aggregator, was attacked by a lightning loan, resulting in a loss of 160,000 DAI, involving more than 10 users. Tether, TrueUSD and USDC were not affected. According to reports, Yeld’s problem is consistent with the previous Yearn.Finance DAI pool vulnerability problem. The official also stated that the affected users will be repaid with tokens, which will be rewarded with income from the DAI pool to make up for some of their losses."

"Later, Yeld.finance officially stated that the 160,000 DAI caused by the lightning loan attack has been returned. This event is suspected to be the work of a white hat, and the official will further update the details."

On "April 19th, 2021", the project had an audit which reported that "No security issues from external attackers were identified." and to "Ensure trust in the project team as they have notable power in the ecosystem."

This is a global/international case not involving a specific country.

The background of the exchange platform, service, or individuals involved, as it would have been seen or understood at the time of the events.

Include:

Known history of when and how the service was started.
What problems does the company or service claim to solve?
What marketing materials were used by the firm or business?
Audits performed, and excerpts that may have been included.
Business registration documents shown (fake or legitimate).
How were people recruited to participate?
Public warnings and announcements prior to the event.

Don't Include:

Any wording which directly states or implies that the business is/was illegitimate, or that a vulnerability existed.
Anything that wasn't reasonably knowable at the time of the event.

There could be more than one section here. If the same platform is involved with multiple incidents, then it can be linked to a main article page.

The Reality

This sections is included if a case involved deception or information that was unknown at the time. Examples include:

When the service was actually started (if different than the "official story").
Who actually ran a service and their own personal history.
How the service was structured behind the scenes. (For example, there was no "trading bot".)
Details of what audits reported and how vulnerabilities were missed during auditing.

What Happened

The specific events of the loss and how it came about. What actually happened to cause the loss and some of the events leading up to it.

Key Event Timeline - Yeld Finance "Lightning Loan" Attack
Date	Event	Description
February 27th, 2021 12:00:00 AM	First Event	This is an expanded description of what happened and the impact. If multiple lines are necessary, add them here.

Total Amount Lost

The total amount lost is unknown.

How much was lost and how was it calculated? If there are conflicting reports, which are accurate and where does the discrepancy lie?

Immediate Reactions

How did the various parties involved (firm, platform, management, and/or affected individual(s)) deal with the events? Were services shut down? Were announcements made? Were groups formed?