Airdrops Under Attack: Can Sybil Farmers Be Stopped?
The explosion of airdrop programs in the crypto world is attracting a large number of users to participate. However, it is accompanied by a rapid increase in attacks from "Sybil farmers" - people who impersonate to steal rewards. Can the Web3 ecosystem stop this wave?
The airdrop craze explodes with Web3 reward points
Over the past three years, blockchain projects have issued more than $26 billion worth of free tokens, a huge figure equivalent to the cost of a series of space missions. This form has developed into an extremely popular marketing and user incentive strategy.
The emergence of Web3 reward points from 2023 has further accelerated this trend. Projects reward points for users performing tasks such as trading, staking or interacting with NFTs. The points are then converted into tokens via airdrops. Although the points are not recorded directly on the blockchain and lack transparency, billions of points have been issued and even traded secondarily.
This environment has created an environment where Sybil farmers, fake users or bots, can exploit airdrops for their own gain.
Sybil Token Hunters Using Fake Identities
“Sybil farmers” is a term used to describe individuals who operate hundreds to thousands of fake wallets to qualify for airdrops. Named after a famous literary character with multiple personality disorder, Sybils pretend to be real users to mine for free rewards and tokens.
Krystyna Kozak-Kornacka, CMO at MarketingFi platform Cookie3, shares:
“They are rapidly developing sophisticated airdrop farming algorithms that mimic real user behavior both on-chain and off-chain – to bypass defense mechanisms.”
Diverse attack methods and counter-attack strategies
1. Loose airdrop conditions are easy to exploit
Many projects set airdrop participation criteria that are too simple, making it easy for Sybils to bypass. Typically, zkSync, a Layer-2 platform, distributed more than 3.6 billion ZK tokens in June. About 46,000 fake wallets collected $94.5 million worth of ZK tokens, causing a backlash in the community because “whales are favored over real users”.
The proposed solution is to distribute rewards linearly based on the amount of assets users hold, instead of transaction fees or completed tasks. This helps to limit small wallets from farming large numbers of transactions to receive unfair rewards.
However, projects often prioritize “fake” on-chain activities to attract investment capital, making the linear solution not widely applied.
2. Reputation & Identity Verification Systems
Many experts believe that building a reputation system is a necessary direction. Like “Proof of Individuality” (PoI), these systems require users to perform actions such as linking to social networks or completing verification tasks to prove they are real people.
Reputation scores are based on a long history of activity, avoiding the dominance of “flash” wallets. At the same time, behavioral analytics can detect suspicious patterns such as task spamming or mass capital movements.
Cookie3 shares:
“By aggregating data from on-chain and off-chain sources, we can determine who is real and who is a Sybil bot.”
3. Cybersecurity and multi-layer authentication
Sybil bots are becoming more sophisticated: automating interactions, masking behavior with exchange addresses, and even simulating interactions that appear “real”. Platforms like CoinList have had to remove over 2.4 million bots from their systems.
Effective defenses include:
IP behavior analysis
Device & browser authentication
Email & social media account verification
Wallet interaction logic checks
However, these mechanisms still need to be supplemented by an independent anti-Sybil system.
Sybil airdrops: A blow to Web3 credibility
Sybil not only damages airdrop projects, but also inflates fake data, deceives investors, and creates the illusion of sustainable growth. After the airdrop, Sybil dumps tokens and withdraws from the ecosystem, causing a sharp decline in project value.
For example, 79% of wallets participating in zkSync left the system after just one month. The ZK token price dropped more than 26% on the first day of listing and has not recovered.
Conversely, is Sybil a “test drug”?
Some argue that Sybils act as… “system testers.” They expose vulnerabilities, test the robustness of distribution systems, and force projects to improve. This view compares Sybils to “vultures” that, although annoying, are necessary to clean up the market.
The Future: Proactive Defense, Smart Airdrops
While it is impossible to completely eliminate Sybils, the crypto industry can significantly reduce their impact if it deploys several strategies simultaneously: