SuperEx Educational Series: The 50 Most Common Types of Blockchain Attacks (Part One · Attack Types 01–18)

We have already written quite a few educational articles related to crypto attacks. There is a huge amount of content in the crypto world that needs education—from basic knowledge points to applied knowledge. In order to better expand the scope of blockchain knowledge education for everyone, we will, in the next three articles, provide a comprehensive educational summary of the 50 most common types of blockchain attacks. This will also include attacks we have already covered, such as Sybil attacks, 51% attacks, cross-chain bridge attacks, and more.

Blockchain is considered the underlying technology for building the future digital economy, and security is the most critical part of its trust mechanism. With the rapid development of Web3, DeFi, cross-chain ecosystems, stablecoins, NFTs, and Layer2, on the one hand, the technical complexity of blockchain systems is rising rapidly; on the other hand, the “window of opportunity” for systemic attacks is also continuously expanding—attackers are not only becoming more professional, more organized, and even commercialized, but many hacker teams already possess R&D capabilities similar to traditional security companies.

Through years of continuous tracking of on-chain attack data, combined with major security incidents across multiple public chains, exchanges, cross-chain bridges, and DeFi protocols, the SuperEx Research Institute has compiled the 50 most common attack techniques in the industry. To make it clearer, more systematic, and more readable, we have split this series into three parts, each around 5,000 words, to help readers systematically understand the full landscape of blockchain security.

This article (Part One) will, from three major categories—mechanism attacks, consensus attacks, and network-layer attacks—deeply analyze the most common first 18 attack types, including their formation mechanisms, attack processes, historical cases, typical losses, and defense systems.

Consensus & Mechanism-Layer Attacks (01–08)

These attacks directly target the most fundamental layer of blockchain—the consensus mechanism, verification logic, and node coordination mechanisms. Once successful, they often bring systemic disasters, so they are the most dangerous and most destructive attack types.

51% Attack / Majority Attack

If the security cornerstone of blockchain is “no one can tamper with the ledger,” then a 51% attack is the most fatal weakness of that cornerstone.

Why is 51% so dangerous? Because blockchain follows only one rule: “the longest chain (the one with the greatest cumulative work) is regarded as the real chain.” When an attacker controls more than half of the hash power or staking weight, they can:

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  Rewrite history
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  Create double-spends (spending the same asset twice)
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  Selectively censor transactions
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  Reconstruct the chain over any period of time
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  And even, in a short time window, put the entire chain into an incorrect state

Extended case: why are small chains especially vulnerable?

For example, ETC was attacked 3 times in just one month in 2020. The reason was not that ETC’s consensus model is bad, but that: the hashpower rental market is highly developed (such as NiceHash), while small chains have insufficient hashpower—so attackers can rent hashpower for a short period and launch a raid attack.

Today, small chains are almost helpless against 51% attacks unless they:

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  Abandon PoW
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  Introduce economic punishment mechanisms (such as PoS slashing)
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  Increase the economic cost of attacks. This is also the fundamental reason why small PoW chains have been continuously shrinking over the past three years.

Selfish Mining

Selfish mining is a precise attack that exploits vulnerabilities in the incentive mechanism. After mining a new block, the attacker does not broadcast it immediately, but instead: accumulates blocks privately, and then, when the competing chain is about to catch up, publishes them to squeeze out the blocks of honest miners, forcing them to waste work. The final result is:

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  The attacker obtains rewards far above their real share
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  Honest miners continuously “waste hashpower”
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  The entire network becomes more centralized. It does not destroy the chain—it distorts fairness.

Maximal Extractable Value

The most hidden, highest-frequency, and most industrialized attack in the blockchain world—MEV is not only an attack, it is a business. It originates from a fundamental reality: miners/validators have absolute power over transaction ordering.

Attack methods include:

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  Front-running: buying in advance
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  Back-running
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  Sandwich Attack: the most vicious
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  Liquidation sniping
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  NFT mint sniping

The latest research shows that the MEV industry has already exceeded $1.5 billion per year in scale, while ordinary users are defenseless.

Timestamp Manipulation Attack

Many chains treat block timestamps as a source of randomness. This leads to attackers being able to, through actions such as:

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  Extending block time
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  Generating blocks with specific timestamps in advance
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  Manipulating the randomness logic inside protocols

Ultimately causing:

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  Lottery systems to be predicted
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  Validator selection by lottery to be controlled
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  DeFi interest rates to be distorted
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  Time-sensitive smart contracts to malfunction. The risk far exceeds what most people imagine.

Difficulty Manipulation Attack

The difficulty adjustment mechanism is the lifeline of PoW. Attackers can manufacture large numbers of low-difficulty blocks, causing:

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  Chain forks to become easier
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  Block production speed to go out of control
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  Node synchronization failures
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  And in more extreme cases: the chain enters a “frozen state,” where no node can continue producing new blocks.

Some small chains have already experienced this. Recovery requires a hard fork.

SPV Attack

Light clients do not store full data, so they are the easiest to deceive. Attackers provide forged:

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  Block headers
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  Merkle paths
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  State proofs

To make victims believe: they have already received payment, and that a transaction has been “successfully confirmed,” thereby causing fund losses at the wallet layer.

PoS Long-range Attack

An old problem for PoS. After buying old validator private keys, attackers can start forging a chain from far back in history and construct a longer new history.

Solutions include:

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  Checkpoint
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  Finality
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  Slashing

Otherwise PoS can have its history easily rewritten.

Nothing-at-Stake (PoS Fork Attack)

PoS block production is almost costless, so validators may:

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  Sign on all forks
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  Support multiple chains simultaneously
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  Causing the network to fail to converge.

This is the fundamental reason why slashing must exist.

Network-Layer Attacks (09–14)

The network is the weakest part of blockchain, and it is also the easiest place for attackers to hide.

Eclipse Attack

Its essence is: isolating a victim node so that it only sees data provided by the attacker.

Common uses:

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  Deceiving miners and making them mine an invalid chain
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  Inducing wallets to accept invalid transactions
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  Assisting 51% attacks (as we mentioned in previous articles)
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  Deceiving consensus voting
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  Manipulating state synchronization.

This is one of the earliest blockchain attacks studied in academia.

Sybil Attack

The attack every Web3 project fears. Attackers use large numbers of fake identities to:

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  Control DAO voting
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  Farm airdrops at low cost
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  Manipulate governance
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  Abuse incentive systems.

Web3 community governance almost always has to face Sybil.

BGP Hijacking Attack

This attack happens at the internet backbone layer, and victims are completely unaware. Attack methods include:

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  Hijacking the target’s IP range
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  Redirecting traffic to the attacker’s machines
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  Conducting man-in-the-middle attacks or traffic hijacking.

Real case: the 2018 MyEtherWallet incident, with losses exceeding one million USD.

DDoS / Flooding Attack

Blockchain’s resistance to DDoS is far harder than the traditional internet, because nodes are fully public. This allows attackers to:

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  Block nodes
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  Fill up the mempool
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  Prevent oracles from syncing prices
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  Cause block delays
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  Artificially create congestion and push up gas fees.

Many projects encounter DDoS before major profit-related actions, suspected to be linked to MEV teams.

Transaction Delay Attack / Gossip Attack

Attackers prevent transactions from propagating in time, creating a time window for:

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  Front-running arbitrage
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  DEX front-running
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  Liquidation front-running
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  NFT mint sniping.

This attack is highly stealthy, because users only see “lag.”

Partition Attack

Attackers artificially split the network into multiple regions that cannot communicate. This will cause:

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  Multiple independent forks to form
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  Huge reorganizations during eventual synchronization
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  Transaction rollbacks and liquidation errors to be triggered.

PoW chains are especially vulnerable, because network latency risk is extremely high.

Application & Protocol Base-Logic Attacks (15–18)

Replay Attack

Attackers broadcast a transaction from the original chain onto a new chain—this can happen when a hard fork is handled improperly. A simple example is that ETH→ETC experienced this after the fork.

Predictable Randomness

Many blockchain systems rely on randomness, but if you:

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  Use block hash
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  Use timestamp
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  Use transaction nonce

They can all be predicted in advance by attackers, leading to:

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  Lotteries being manipulated
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  NFT rarity being “chosen” by attackers
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  Validator selection mechanisms being manipulated.

Randomness attacks are extremely common.

Signature Malleability

Attackers perform mathematical transformations on signatures, causing:

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  Transaction hash changes
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  Business logic failures
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  Repeated withdrawals
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  User mis-operations.

Bitcoin suffered from this issue early on, and later solved it through SegWit.

Gas Manipulation

Attackers pay high gas fees to execute transactions before users. Common scenarios:

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  DEX front-running
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  Competition for liquidation priority
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  NFT whitelist attacks
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  High-frequency arbitrage.

This is one of the most common economic attacks on-chain, and a core tool of MEV.

Part One Summary

This article explained the first 18 types of attacks among the 50, covering the three most core layers of blockchain:

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  Consensus mechanism attacks (most dangerous, systemic)
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  Network communication attacks (highly latent, most stealthy)
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  Underlying application logic attacks (high frequency, high damage, common among novice teams).

The common characteristics of these attacks are:

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  Difficult to defend completely
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  Highly complex.

Once successful, they cause chain-level or protocol-level disasters, and attackers often have professional capabilities and funding, which allows many attack types to be combined into “composite attacks.”

The SuperEx security team has long studied these underlying attack patterns, and continues to introduce response strategies into exchange systems, on-chain interactions, compliance architectures, and security risk controls.