Blockfence
1.1K posts

Blockfence
@blockfence_io
Investigation and protection layer for wallets, exchanges and enterprises against scams and fraud.





Indodax(@indodax) was hacked for $22M 10 hours ago, including: 6.14M $USDT; 1,047 $ETH($2.48M); 25 $BTC ($1.41M); 2.2M $MATIC($849K); 1.4M $ARB($749.6K); 2M $ENA($465K); ... The hacker has converted most of the stolen assets into native tokens and currently holds: 5584 $ETH($13M); 16.74M $TRX($2.56M); 6.84M $POL($2.55M); 25 $BTC($1.41M); platform.arkhamintelligence.com/explorer/entit…


Identification Of Malicious Extension Over the last week, we received reports that a small number of users using Solana DeFi got drained. After extensive investigation, we have identified a malicious Chrome extension called “Bull Checker” that had targeted users on several Solana-related subreddits. Users with this extension would interact with the dApps as per normal, have the simulation show up as normal, but have the possibility of their tokens being maliciously transferred to another wallet upon transaction completion. If you have this extension (or similar extensions with extensive permissions you cannot trust), please remove it immediately. Note that there is no vulnerability found in any of the dapps or wallets. A report with all the key technical details, including why the simulation looked normal, is available at: jupresear.ch/t/identificati… For the report, we collaborated with @0xslipper from @Offside_Labs who was extremely helpful for much of the technical analysis. Much thanks to @blowfishxyz, @RaydiumProtocol and @phantom who also reviewed this post too. Example Transactions Here are 2 examples of transactions that have interacted with the malicious program 5UMucMksJweA1AtgyxrK8DJeBXr3DQGEGRs5Kkq2pZjr solana.fm/tx/5krgaq2FTZA… solana.fm/tx/3wbxDWWzoHt… In both cases, malicious instructions were added to regular Jupiter and Raydium instructions, and the resulting transaction was signed by the user as per normal, but had their tokens and authority transferred to the malicious address. The Suspected Extension: Bull Checker Upon further investigation of several affected users who have been drained by the same program, we have identified an extension called “Bull Checker”, which has the permissions to read and change all the data on the website, as a potential cause. Raydium has confirmed that their affected user has the same extension installed. Bull Checker is supposed to be a read-only extension that allows you to view the holders of memecoins. There should be no need for an extension like this to read or write data on all websites. This should have been a major red flag for users, but apparently several users continued to install and use the extension. After installing Bull Checker, it will wait till a user interacts with a regular dApp on the official domain, before modifying the transaction sent to the wallet to sign. After modification, the simulation result will still be “normal” and not appear to be a drainer. Technical Analysis For a full technical analysis, including why the simulation check looked normal, how the drainer tx worked, and what the extension code did, please refer to the jupresearch post here: jupresear.ch/t/identificati… Targeting Memecoin Traders In addition to the above information, while researching “Bull Checker” we discovered that it was publicised by an anonymous Reddit account, “Solana_OG”. This person appeared to target users looking to trade memecoins, and lured them to download the extension. Links: reddit.com/r/solana/comme… reddit.com/r/solana/comme… Key Safety Habits While we have identified one malicious extension, there might still be other malicious extensions out there. 1. If you suspect an extension contains malware, particularly if they have both “read” and “change” permissions, uninstall it immediately. 2. Do not trust something just because someone mentioned it on Reddit or other media and it has many upvotes. Astroturfing and social engineering for the purpose of scamming are very real. 3. Extensions that request for extensive permissions are highly suspicious. An extension like Bull Checker should not need to read and modify all your website data. You should have an extremely high degree of confidence in an extension before you start using it. 4. In addition, Blowfish has released a new guard instruction feature called SafeGuard that prevents all simulation spoofing attacks. It’s currently being adopted by multiple Solana wallets and will likely be useful in prevent such future attacks. Conclusion Stay safe out there, and don’t install extensions that can read/write data unless you are really sure. Many thanks to Siji from Offside Labs, Blowfish, Raydium and Phantom for assisting in this investigation.




🚨 Beware of Rugpull in #memecoin PVP world! A FAKE $CATDOG on #Solana has recently executed a #RugPull, causing significant losses for unsuspecting investors. 🐱🐶 The deployer initially added a mere 1 $SOL of liquidity. However, he true intentions became evident as he proceeded to spend a total of 800 $SOL to purchase 99.87% of the supply at a low price. 😱 Shockingly, just 10 hours later, he executed a RugPull for 2061.22 $SOL, resulting in a devastating 100% price drop. ❌ solscan.io/tx/4cmgV5jNbuJ… 🔍Before purchasing any memecoins or investing in any project, it is crucial to verify the contract, conduct thorough research, and exercise caution. Stay vigilant and be aware of potential scams and rugpulls in crypto space. 🕵️♂️ #CryptoSafety #StayInformed #DYOR



















