DeFi Devastation: $92M Hacked in April - Are Your Funds Safe?

April 2025 turned out to be a rough month for decentralized finance (DeFi). 22 Hackers hacked. Hackers stole the most ever, stealing a shocking $92 million through multiple hacks. Here at GreedyChain.com, we know that you’re serious about outpacing the competition in Web3. To be successful you need to understand what the vulnerabilities are and figure out the best ways to protect your assets. Here’s a rundown on what transpired and, more importantly, what you can do to change that future.

Understanding the April 2025 DeFi Hacks

The compromises of April 2025 were not isolated, unrelated incidents. More importantly, they uncovered key weaknesses that attackers have cruelly taken advantage of. Knowing these attack vectors is the first line of defense against whatever comes next. The biggest takeaway? Complacency is your enemy.

The largest such incident was due to Loopscale. Attackers took advantage of a bug in the protocol’s valuation of RateX PT tokens. Unlike most DeFi hacks that wait for an attacker to compromise private keys off-chain, this attack went after the smart contract vulnerability itself. This signals that there was a flaw in the code itself that was taken advantage of to siphon value from the protocol.

Loopscale Exploit: A Deep Dive

The Loopscale hack recently served to emphasize this importance, as a lack of secure smart contract design led to its exploit. Through creative usage of protocol mechanics, the attacker was able to alter the perceived value of RateX PT tokens, allowing them to drain funds from the protocol. The problem didn’t stem from someone hijacking a private key. Rather, it was a result of a bug in the underlying assumption of the smart contract’s logic.

This incident highlights the continued importance of thorough code audits and security testing. Protocols must take proactive steps to ensure that their smart contracts are thoroughly audited before launching to mainnet. The Loopscale hack should remind us all that the most innocuous-seeming bugs can have catastrophic effects.

Attack Vectors: Where the Weaknesses Lie

The April 2025 hacks were not restricted to a single vulnerability. The attackers leveraged all sorts of different attack vectors—from price oracle exploits, smart contract vulnerabilities, to flash loan attacks. As the name indicates, they are each different attack vectors, and it’s important to understand the difference to craft effective mitigation strategies.

Price Oracle Manipulation

Oracles are an essential component of the DeFi stack, delivering outside-of-chain data to smart contracts, such as price feeds. At the same time, they can be an acute point of vulnerability. Oracle manipulation attacks include when attackers find ways to exploit weaknesses in an oracle’s architecture to return malicious data. Enormous financial catastrophes can result, as smart contracts rely on this data to perform trades and other tasks. If the data is garbage, it undermines the whole process.

Oracle manipulation can take many forms. Flash loans can be used to dramatically pump or dump the value of a cryptocurrency. This manipulation deceives the oracle and results in a false negative reported value. The October 2022 exploit of Mango Markets siphoned off an eye-popping $117 million from the protocol. This recent incident serves as a textbook case of an oracle manipulation attack.

Smart Contract Flaws

From the Loopscale hack, for example, any mistakes or vulnerabilities in smart contract code are a jackpot for adversaries. These flaws may be as benign as coding oversights to logical vulnerabilities of greater intricacy. These weaknesses can enable attackers to or otherwise use stolen funds, alter data, or undermine the protocol’s overall integrity. Whatever the reasons, the danger is very real.

Flash Loan Attacks

This makes flash loans one of the most powerful tools in all of DeFi. They enable users to withdraw vast sums of crypto—thousands of dollars worth—without any collateral, as long as it’s paid back in the same transaction. It is this feature that can be abused in flash loan attacks. Attackers further distort the market by using loans to artificially increase crypto cost. The perpetrators then use these artificially inflated prices to secure even larger loans or abscond with valuable collateral.

Of the approximately 150 attacks, 45 were funded through flash loans. From the birth of DeFi until now, hackers have stolen a projected $6.5 billion at least. Flash loans often take the spotlight when it comes to these hacks. The attacks analyzed resulted in losses of over $985K, highlighting the need for robust security measures and the importance of using multiple trusted oracles for price determination.

Practical Steps to Mitigate Risks

Here are some practical steps you can take to mitigate the risks of DeFi hacks:

For Users:

• Do Your Research: Understand the protocols you're using. Look into their security practices, audit history, and team reputation.
• Diversify Your Holdings: Don't put all your eggs in one basket. Spreading your assets across multiple protocols reduces your exposure to any single point of failure.
• Use Hardware Wallets: Store your private keys securely offline using a hardware wallet.
• Stay Informed: Keep up-to-date with the latest security threats and best practices in the DeFi space.

For Developers:

• Rigorous Code Audits: Engage reputable security firms to conduct thorough audits of your smart contract code.
• Security Testing: Implement comprehensive security testing procedures, including fuzzing, static analysis, and penetration testing.
• Risk Management: Develop a robust risk management framework to identify, assess, and mitigate potential security threats.
• Stay Updated with Current Standards: Staying up-to-date with the latest developments and best practices in smart contract security is crucial.

Tools and Best Practices for Developers:

• Utilize security tools: Mythril is an all-in-one smart contract security best practices tool that can help identify potential vulnerabilities.
• Visualization tools: Visualization tools, such as Solidity Visual Auditor, can bring a safety-first syntax viewpoint and help identify potential security flaws.
• Keep it clean and simple: Overcomplicating smart contracts can lead to unforeseen issues and confusion for those interacting with the contract.
• Embrace asserts but tread lightly: Asserts can be used to validate conditions, but they should be used judiciously to avoid unnecessary gas costs.

The Ever-Evolving Landscape of DeFi Security

DeFi security is an ongoing battle. Attackers are always coming up with new techniques, and protocols need to be on their toes to avoid falling behind. CVE-2025-22457 is a critical vulnerability affecting Ivanti’s Connect Secure, Policy Secure, and ZTA Gateway products. At the same time, CVE-2025-30406 and CVE-2025-24813 open up a security hole in Apache Tomcat. Collectively, these vulnerabilities highlight the multifaceted cybersecurity arena that DeFi operates in. It is an incredible opportunity, but any weakness in the underlying infrastructure is a chink in the armor.

Here’s an overview of the vulnerabilities used in the April 2025 DeFi hacks. It is by following through on the mitigation strategies listed above that users and developers will significantly lower their risk. So nameless developer, do not forget, in the world of DeFi security is a shared responsibility.