A professional hacker installed a sweeper bot on a compromised crypto wallet containing $90K of staked AVAX. We had one week to save these funds on Avalanche’s P-Chain before the hacker could claim them. This is the story of how we coded our own bot, fought in the dark forest of the blockchain, and emerged victorious.
Introduction
A crypto account’s private key had been stolen, and a malicious bot was installed on the wallet. Inside this compromised account, there was $90,000 worth of staked AVAX, set to unlock in exactly one week. Once that staking period ended, the hacker would try to claim everything.
Here’s the catch: because a sweeper bot was connected to this wallet, no normal transaction could be executed from the account without being instantly “swept” by the hacker. Even sending a tiny bit of AVAX as a fee would trigger the bot to steal it, making it appear impossible to recover the staked funds.
But in the world of blockchain security, nothing is truly impossible. We had seven days and a powerful community to help. This story details how we overcame a dangerous bot, used our knowledge of Avalanche’s P-Chain, and managed to rescue $90,000 of AVAX.
Who Am I?
For those who are reading me for the first time:
“I am a blockchain security specialist and smart contract auditor. I’ve audited numerous crypto projects and have spent the last three years recovering lost tokens from compromised wallets. My primary expertise is Bot Warfare in blockchain — specifically how bots operate with smart contracts.”
You can find me on Twitter (X) at @0xSmartContract
Over the years, I’ve helped rescue tokens from countless compromised wallets. If you ever find yourself lost in the “dark forest” of the blockchain, you’re in the right place. For more examples of rescue operations, feel free to check out my previous HackerNoon story on bypassing a sweeper bot to save $26k worth of tokens: How Did We Bypass the Sweeper Bot and Saved $26K Tokens in the Dark Forest of Blockchain?
I receive at least four or five messages daily from people worldwide whose accounts have been hacked. There’s been a surge in the last year, likely due to the increasing global interest in crypto — and thus, more criminals focusing on it. Bots are often the culprit, since they excel at sweeping and front-running. They can also excel at arbitrage, MEV (miner extractable value) strategies, or instantly buying meme tokens. But they’re especially formidable at preventing a compromised wallet from making any transactions until the attacker is ready to steal funds.
The Call for Help: A 1-Week Deadline
“I got a message from a user. Their seed phrase was stolen, and all their immediately available funds were drained. But the hacker left a bot behind to grab anything else that entered the wallet. Now, the hacker was waiting for $90,000 of AVAX to unstake in 7 days on the Avalanche P-Chain.”
The Problem: Any attempt to send a transaction from this wallet (even gas fees) would be instantly swept by the hacker’s bot, making it seemingly impossible to transfer out any additional assets.
The Hacker’s Method: Hackers often install these bots to ensure that once they compromise a wallet, no one else can successfully move any funds without paying them first. If they detect any incoming coins or if the victim tries to stake/unstake, the bot instantly sends those coins to the hacker’s wallet.
In this case, the hacker also posed as a real blockchain project official on LinkedIn — a highly convincing social-engineering tactic.
Our victim was part of one of the most robust communities in crypto: Avalanche. At an Avalanche event, the victim had met a technically savvy community member, @koaservatt, who was ready to help. Recognizing the complexity of the situation, @koaservatt connected the victim and me. From that moment onward, we formed a small but determined rescue team.
“Shoutout to @koaservatt for organizing the rescue from start to finish, sharing unique insights about Avalanche’s P-Chain staking mechanics, and staying awake for nearly a week. This is the power of community support in the crypto world.”
Planning the Bot vs. Bot Battle
We had seven days before the stake ended. The moment that stake became transferable, either the hacker’s bot would claim the AVAX — or we would. To succeed, we needed a carefully crafted plan and our own counter-bot. Below were the main challenges:
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A Professional Thief
“The hacker had stolen from many people and was online 24/7. That was their only job — to steal. But we have day jobs, so our bot has to be exceptionally sharp and fast.
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Unfamiliar Territory on P-Chain
“The Avalanche P-Chain has different transaction logic compared to typical EVM (C-Chain). None of the usual EVM-based approaches would work here. We had to revisit Avalanche’s documentation, transaction formats, and code.”
I always recommend reading official documentation and open-source repositories to fully understand a blockchain’s structures. Here are some resources we used:
Also, if you want more insight into how I approach bot architecture and visualize smart contract code, check out my HackerNoon piece: Smart Contract Codes: How You See It vs. How a Hacker Sees It
7-Day Countdown Begins
Below is how the week progressed as we raced against the clock:
Days 1 – 2: Deep Dive into Avalanche P-Chain
“If you want to fight bots on a blockchain network, you need to study the network at the code level.”
For the first two days, I immersed myself in Avalanche’s GitHub repo and official documentation. The P-Chain’s transaction mechanisms differ from typical EVM logic, so a thorough understanding was crucial.
Day 3: Need for a Wallet & Testing Environment
“We needed to test multiple scenarios on Avalanche’s P-Chain. However, the only official wallet app for P-Chain, ‘Core,’ was suddenly taken down by the project team. This caused a significant delay.”
Without a standard wallet interface, we had to devise our own test environment and scripts to experiment with P-Chain transactions. This set us back a couple of days.
Day 4: Hacker’s On-Chain Moves
“I noticed on-chain that the hacker had begun making preparations. Clearly, they were also getting ready for the staking’s end. Time was running short.”
I meticulously mapped out every possible transaction the bot might make and cross-referenced them with how our counter-bot could respond. We needed speed and precision.
Days 5 – 6: Final Testing of Our Rescue Bot
“Recalling Dan Robinson’s legendary article about battling bots in Ethereum’s ‘Dark Forest,’ I remembered his warning: ‘There is a high probability you will underestimate these bots.’ So I tested everything multiple times.”
We wrote the code, tested with small amounts, and refined. There were many small “surprises” we integrated to outsmart the hacker’s bot on the P-Chain.
For those intrigued by these types of high-stakes blockchain bot scenarios, here’s Dan Robinson’s influential piece: Ethereum is a Dark Forest
Final Day: Staking Unlock & Showdown
“When the stake ended, our rescue bot had to execute its transaction at the exact second that AVAX became available. It was either us or the hacker.”
We deployed our bot — designed to process every step atomically:
- Immediately transfer the AVAX out to a secure wallet address.🎯
- Prevent the hacker’s bot from front-running our transaction by leveraging certain P-Chain transaction nuances and meticulously timed calls.🎯
It worked. Our bot outran the hacker’s bot and secured all $90,000 worth of AVAX. The transaction settled, and we quickly confirmed the funds were safe in a newly generated, uncompromised address. 😅🎉🎊
“We succeeded! In the dark forest of the blockchain, we emerged victorious and saved $90,000. It was a huge relief!” 🥇
Conclusion
This intense, week-long battle on Avalanche’s P-Chain highlights several important lessons:
- Blockchain Documentation is Key- Understanding the fundamentals of how transactions work on a specific chain is the difference between success and failure.
- Bots Never Sleep- Sweeper and front-running bots can be relentless. If your private keys are compromised, any normal transaction is nearly impossible. You need a robust, creative plan (and often, a custom bot) to stand a chance.
- Community Support Matters- Without the Avalanche community (especially @koaservatt), we might never have achieved this rescue on time.
- Never Underestimate a Hacker’s Bot- They are fast, dedicated, and perfectly tuned to the environment. Your code must be faster and more cunning.
- Always Safeguard Your Seed Phrases- Prevention is the best defense. Never share your seed words — especially not on suspicious websites or with strangers on social networks.
Final Word
In the end, we beat the odds, overcame the hacker’s sweeper bot, and secured $90,000 of staked AVAX. If you are ever lost in the blockchain’s dark forest, remember that with enough technical knowledge, community support, and a bit of creativity, there’s almost always a way out.
Got a story or need help? I only use X (Twitter) for communication and receive messages daily from people seeking recovery assistance. If you’d like to brainstorm about recovering tokens from a compromised account, feel free to reach out.
If you want to support or brainstorm about the funds that need to be recovered from the hacked accounts, you can send me a message on my twitter account.
References & Further Reading:
Happy hacking 🤖,0xSmartContract
