According to statistics from the Research and Development Department of the Vietnam Blockchain Association (VBA) based on reports by Chainalysis and Immunefi, the world has recorded 657 cryptocurrency exchange hacks, causing losses of up to 12.8 billion USD in the period from 2020 to February 25, 2025, warning of cyber security risks globally.
2022 is considered the "peak" year with 219 cyber attacks, causing a loss of about 3.8 billion USD. Although 2025 is only the first 2 months, the market has recorded 20 hacks with a total amount of nearly 2.5 billion USD.
Famous hacks in the period 2020 - early 2025
Bybit was the latest to be hit hard in early 2025, with $1.5 billion stolen. This was followed by the Ronin hack (2022) with a loss of $615 million, affecting the network of the game Axie Infinity, due to a cross-chain bridge exploit.
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The third largest hack in the past five years was Poly Network (2021) with $610 million stolen, but the hacker returned most of the assets after negotiations.
The attack on DMM Bitcoin (2024) resulted in a net withdrawal of $300 million from the exchange. The incident stemmed from a private key compromise, which led to the immediate shutdown of DMM Bitcoin.
Ranked 5th is the attack on Kucoin exchange (2020) with an amount of 281 million USD, mainly targeting Ethereum and Bitcoin, causing panic in the blockchain community.
Common forms of attack
According to statistics from the VBA Research and Development Department, from 2020 to February 25, 2025, there are 3 main forms of attacks in the cryptocurrency field including: private key compromise, cross-chain bridge attack and smart contract exploit.
Private key compromises accounted for 36% of all hacks, with 235 incidents and a loss of $5.6 billion (44% of total losses). These attacks typically occur on centralized exchanges (CEXs) or personal wallets, where hackers steal private keys to gain control of assets. In 2024, cybercriminals stole $1.34 billion through this method.
Attacks on cross-chain bridges also caused significant damage. There were 79 hacks in this category, accounting for 12% of the total, with an estimated $1.25 billion in losses. This highlighted the significant risks of transactions between unsecured blockchain networks.
Meanwhile, smart contract exploits were the most common method in the blockchain space, accounting for 58% of all hacks with losses of up to $6.95 billion. Hackers took advantage of vulnerabilities in smart contract code to launch attacks and steal assets from decentralized finance protocols. In 2022, a total of 150 hacks of this type caused a loss of $2.4 billion, accounting for 82.1% of the total amount stolen.
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| Dr. Do Van Thuat, Technology Expert of Vietnam Blockchain Association, Member of the Scientific Council of ABAII Institute |
Explaining why smart contracts are often targeted, Dr. Do Van Thuat, Technology Expert of Vietnam Blockchain Association, Member of the Scientific Council of ABAII Institute, said that smart contracts are transaction rules programmed and deployed for different applications (dapps) on a blockchain network. Although blockchain is highly secure, the security of its applications (for example, decentralized finance DeFi) also depends on the set of operating rules specified in the contract. If the rules are flawed or have vulnerabilities, they will be less secure and exploited, leading to financial losses. This is similar to civil and business contracts in real life.
“Smart contracts hold a lot of assets, process billions of dollars in transactions every day, and anyone can read and interact with the contract, making it an easy target for hackers. Returning to the attacks on Bybit, Ronin, and Poly Network, the common point is that these platforms store assets in multi-signature smart contracts, which means that they require simultaneous digital signatures of approval from many people (who are managing the contract) to withdraw money. Those contracts are open source, thoroughly audited, and quite popular,” said Dr. Thuat.
In a simple explanation of the Bybit hack, Dr. Thuat described that in the contract using the open source multi-signature wallet Safe, hackers actually attacked the smart contract managers (each person holding a secret key is authorized to sign the contract). In some "sophisticated" way, hackers learned about the managers, tricked them, and made them allow the thieves to withdraw money. The smart contract is like a carefully locked asset warehouse, the thief cannot break the lock but can trick the key holder to open the door for the thief to enter and take the money away.
Going deeper into the technical side, user interfaces (UX/UI) are often managed and operated through traditional IT systems (ie Web2) on cloud platforms. Hackers exploited Safe’s server vulnerability on AWS, thereby injecting malicious information, hiding it, making administrators subjective, signing permission for hackers to change the contract rules, from which hackers can withdraw money.
“This attack has been analyzed by many prestigious security units in the world, including in Vietnam,” said Dr. Thuat.
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| Dr. Nguyen Trung Thanh, Chairman of Web3 Committee, Vietnam Blockchain Association |
Sharing the same opinion with Dr. Thuat, Dr. Nguyen Trung Thanh, Chairman of the Web3 Committee, Vietnam Blockchain Association, said that carrying out an attack is not simple and requires many conditions. The attacker has carefully, persistently and meticulously monitored to identify weak links in the system, especially Web2 components and human factors.
“These weaknesses do not always exist, but may only appear when there is negligence in processes such as golive (putting products into the real environment), human resource management, open source code management, or when using products from third parties that are considered "reputable" but are attacked. Some vulnerabilities may have existed for a long time but were not discovered and fixed in time. When hackers discover these weaknesses, they will become targets for exploitation to carry out intrusions,” Dr. Thanh assessed.
Dr. Nguyen Duy Lan, Technology expert of Vietnam Blockchain Association, Co-founder and Vice President of Veramine Inc., Seattle, USA, analyzed that cryptocurrency attacks often combine exploiting vulnerabilities and using social engineering techniques, targeting different weaknesses in both Web 3 and Web 2 parts of the system. For Web 3, logical errors in smart contracts are often exploited, such as unsafe handling of special cases (corner cases), errors in money addition and subtraction operations, and vulnerabilities in cryptography.
“Meanwhile, the Web 2 part can be attacked in a variety of ways, often focusing on the secret keys of users, administrators or bridges. If these keys are protected by hardware security devices such as Hardware Security Management Systems (HSM) or cold wallets, theft will be almost impossible, although it is still necessary to guard against encryption errors that can create predictable keys. At that time, the attacks mainly aim to gain access to or bypass the protection functions of these keys, by penetrating the software system that manages the keys, installing malware to deceive the system and administrators,” Dr. Lan assessed.
What is the solution for Vietnam in the future?
The increasingly sophisticated attacks by hackers have caused a major impact on the market and affected the psychology of investors. However, Dr. Thuat affirmed that the main cause lies in the administrators of smart contracts being deceived, not the contracts having vulnerabilities. Most contracts are still safe, the potential for blockchain applications through smart contracts is still very open and promising.
To minimize the risk of being hacked, VBA's technology experts believe that contract developers and operators (holding secret keys) must always put safety first, consult information security and system security units to prevent hackers and minimize risks.
“Investment in technology, people and security processes is essential, including developing security tools, conducting testing, auditing, and penetration testing. It is also necessary to set up an activity monitoring system and apply artificial intelligence (AI) to detect abnormalities. Security needs to be integrated into the entire process of developing cryptocurrency systems, from design to deployment, and can learn from the security processes of the traditional information technology industry,” said Dr. Nguyen Duy Lan.
Dr. Nguyen Trung Thanh expressed his opinion that ensuring absolute safety in the field of information security is impossible, it is only possible to minimize risks and prepare for possible situations.
“Technology investments should not be taken lightly. Although they may save costs in the short term, a lack of focus on security will lead to serious consequences in the long term. The prestigious members of the Vietnam Blockchain Association are always ready to accompany and support large corporations in ensuring the safety of digital assets,” said Dr. Thanh.
From the recent hacks of crypto-asset exchanges, Mr. Phan Duc Trung, Chairman of the Vietnam Blockchain Association, called for Vietnam to quickly establish information security standards and crypto-asset management. “As the digital asset market continues to grow, the lack of a clear legal framework not only makes investors vulnerable but also limits the potential of the blockchain industry. Only with the law as a foundation can we build a trustworthy crypto-asset ecosystem that both protects users and promotes innovation,” Mr. Trung emphasized.
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