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Showing 20 of 31 results by BTCtester.com
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Board Bitcoin Discussion
Merits 2 from 2 users
Topic OP
6000 coinbase clients hacked
by
BTCtester.com
on 02/10/2021, 18:20:17 UTC
⭐ Merited by Fortify (1) ,BrianH (1)
Another example why using central exchanges is risky. The hackers knew private data of the users. One corrupt employee or one successful hack and bad guys capture your email, home address, phone number and sell it to local criminals who might knock on your door then best encrypted wallets are useless. Cryptocurrencies are designed for peer to peer usage. If you change it into peer to bank to peer then this adds some risks.

https://www.reuters.com/business/finance/coinbase-says-hackers-stole-cryptocurrency-least-6000-customers-2021-10-01/
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Board Bitcoin Discussion
Topic OP
A whale moved $2bn in bitcoin 540 times in a short time frame
by
BTCtester.com
on 21/09/2021, 17:42:41 UTC
On Sep 10 someone consolidated bitcoin from 829 addresses into address 32ZHZYwYATJj8jtoFvUQ9HEz7UoWnLgG5U then he moved the 45.5k BTC 540 times with 720 cash outs (total 1k BTC) at 26 exchanges and on Sep 14 he split the remaining 44.5 BTC again into 51 addresses. From the new addresses similar behavior continues.

This is a strange behavior. A smart money launderer would probably not co-spend 829 addresses. And a honest person likely would not do 540 transactions for cashing out because one typo or software error could move the $2bn unintentional as fee to a miner and he could have done this in one or two transactions.

What's your thought?

P.S:
This demonstrates how easy tracing bitcoin is and that a scammer has no reason to sleep well even not after years. As a first indicator for traceability one can use the Bitcoin privacy score of any BTC address, the lower the score the better your chances to find traces to exchanges where the scammers funds can be frozen.
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Board Bitcoin Discussion
Re: My friend got arrested in a p2p scam
by
BTCtester.com
on 15/09/2021, 18:03:09 UTC
There are major risks using central exchanges:
  • They might block withdrawal
  • They get hacked and your deposits are gone
  • Their client database is hacked or a corrupt employee sells it. Then it's sold in the darknet to local criminals which knock on your door to get your coins
  • your coins are trackable, so this is a privacy concern

So decentral peer to peer exchanges might be the better choice: Your keys, your bitcoin!
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Board Bitcoin Discussion
Re: My friend got arrested in a p2p scam
by
BTCtester.com
on 26/08/2021, 16:34:19 UTC
Use decentral exchanges (DEX) like bisq.network and deal only with signed accounts which have some months account age or with whom you dealt before. And better you do three trades with amount X instead of one trade with amount 3x. And accept the fiat payment only in case it's from the same person and account number as registered in the DEX. Otherwise return it immediately and don't release the coins.

Doing so you have no KYC and less risk to get involved into triangle scams where e.g.

A buys bitcoin from you for $ 500 and you give him your bank account number
A sells a washing machine at ebay to B for $500 and gives B your bank account number
B sends you $500 and you release the bitcoin
B then goes to bank and police because he never got the washing machine
Police comes to you because the first impression is you're the ebay fraudster
The outcome is you have $500 in bitcoin less, A has $500 in bitcoin more and for B it was just trouble but no money loss or gain.
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Board Beginners & Help
Merits 1 from 1 user
Re: Strange email from Binance
by
BTCtester.com
on 03/08/2021, 21:22:27 UTC
⭐ Merited by TimeTeller (1)
The senders address can be faked. But what do they want from you. Is there a lik in the email asking you to visit a webpage?
Why not logging into your binance account to see if there is as well a message. But don't klick on links in emails, please.
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Board Bitcoin Discussion
Re: 2.66 BTC fee for one transaction
by
BTCtester.com
on 26/07/2021, 08:53:21 UTC
I don't think that's the reason and it won't help to make your BTC clean and actually if someone mine that blocks with that transaction it's randomly distributed to the miners(from pool to miners). They can not control this to give the fee to selected miners and only pool operators can manually select what transaction they want to include on the block but by default most pools automatically choose a transaction with a large transaction fee.

You don't need to broadcast your transaction. You can just inform the miner cooperating with you to add it to the next block. And the code is open source. It can be changed.
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Board Bitcoin Discussion
Topic OP
2.66 BTC fee for one transaction
by
BTCtester.com
on 25/07/2021, 21:51:30 UTC
Who decides about the fee amount for a bitcoin transaction? It's the sender alone, he might have delegated this decision to his wallet or provider. E.g. in BTC transaction 3ba0c9eaf3185898164518cda7e3433d1d2049188d737f2b2a7e188aaeb8b4de someone sent 0.01088549 BTC and paid a 2.66038352 BTC fee.

The standard explanation for this is that it was a senders mistake. But it could be as well money laundering. If the sender is the miner or a person dealing with the miner it could be that this fee close to $100k was paid by intention to convert bitcoin from criminal activity into miners coins which are usually seen as innocent virgin coins.

How to investigate this? If the transaction was not in the mempool of the most nodes or if the transaction wasn't in orphaned blocks at similar time then it's very suspicious that the fee was given to the miner by intention to launder the coins.
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Board Bitcoin Discussion
Merits 1 from 1 user
Re: The stupid 307 BTC hacker (Exmo exchange)
by
BTCtester.com
on 25/07/2021, 21:06:01 UTC
⭐ Merited by buwaytress (1)
Thanks for all the additional information, it does seem highly unusual that someone would go through all that manual obfuscation only to link his final spend into an exchange (Binance, for that matter) with unspent outputs from the original. Suppose no one's immune from noob mistakes, probably did a sweep from the wrong wallet.

This was just one example. He did several mistakes. Moving the coins from address to address in long chains and then crossing the chains which isn't smart. And there are a lot of little side transactions to exchanges. This might come from the fear that higher amounts attract more attention.
I think the idea is that nobody can follow this up in 200 steps depth in the blockchain because there are billions of paths. But I analysed patterns of these kinds of obfuscation behavior. They are totally different from a normal random transaction chain with 200 steps.

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Board Bitcoin Discussion
Re: The stupid 307 BTC hacker (Exmo exchange)
by
BTCtester.com
on 25/07/2021, 20:56:02 UTC
A bit too lazy to look this up but couldn't you at least show some links or give us the address to look at? You'd have probably taken care to do this had this been your own findings, but then my first Google search didn't show anything about this, so assuming this is new and hasn't made it rounds to English-speaking channels yet. So come on, don't be shy. Share.

P.S. Make up your mind. Is this "hacker" stupid or cunning?

1A4PXZE5j8v7UuapYckq6fSegmY5i8uUyq is the BTC address where the hacker collected the stolen funds first. The findings are from myself. I think he is a cunning hacker but stupid in hiding his traces ;-)
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Board Bitcoin Discussion
Topic OP
The stupid 307 BTC hacker (Exmo exchange)
by
BTCtester.com
on 25/07/2021, 11:13:56 UTC
The cunning 307 BTC hacker of exchange Exmo is far from being able to escape undetected with the captured Bitcoin. Although the hacker tried to obfuscate the origin of bitcoin through hundreds of transfers, it is easy to prove that he deposited 15.7 BTC after 207 transactions on the Binance exchange on February 26, 2021. How is this possible?

Manually created BTC obfuscation transaction chains have a significantly different pattern than chains created by natural transactions in the blockchain. And the fraudster made the additional mistake of using the bitcoin in the 207th step together with other unspent outputs from the heist in a common transaction. The 207 obfuscation transactions were thus completely useless for the scammer, only the miners enjoyed the transaction fees.

This is just one of many mistakes the fraudster made. The next logical step for Exmo is to use the analysis results to freeze the fraudster's crypto assets on the involved exchanges.
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Topic
Board Bitcoin Discussion
Africrypt $3bn heist
by
BTCtester.com
on 27/06/2021, 15:56:50 UTC
I wonder if there are really many Africrypt victims or if this is a fake heist where international gangs try to launder money. Unbelievable that people give their millions to an 20 years old investor. If there are real clients it would be interesting to see victims deposit bitcoin addresses in order to trace the wallets in the blockchain until it goes to exchanges.

https://www.itweb.co.za/content/j5alr7QaVRg7pYQk
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Board Bitcoin Discussion
Re: 180 Coins Stolen From my wallet 1GpUcrJ1Zo6ZJWgw7HQT7nADijY5a3dcCh
by
BTCtester.com
on 23/06/2021, 11:49:03 UTC
I just did a quick look into your old case and found traces to bitpay.com and if I'd analyse further I'd find more. Did you ever try to trace the scammer?
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Board Bitcoin Discussion
Re: Sextortion - more than 4000 BTC cashed
by
BTCtester.com
on 20/06/2021, 16:50:46 UTC
Making a mistake is not always the result of laziness, it may simply become overwhelming at some point realistically speaking.

Or are you deeply into protocol and analytical stuff or just a hobby?

Yes, only once of 500 times at 3am in the night a little mistake and the privacy is weakened.
It started as a hobby but in the meantime I do it professional.
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Board Bitcoin Discussion
Re: Sextortion - more than 4000 BTC cashed
by
BTCtester.com
on 17/06/2021, 18:49:09 UTC

I see what you are saying and I know that companies like Chainalysis can go far beyond what many people think. But if you get your money into Monero and you send it a few steps ahead, maybe just divide it into a couple smaller transactions onto various Monero addresses, how are you going to identify the scammer? Isn't then the only way to crack Monero itself? I see why Bitcoin is relatively easy to trace even when mixers are used, but for as long as you are careful with hiding your IP and you are not unlucky using an infected TOR node, there is no way to really find you before any exit. Am I wrong?



If you have bitcoin on 10 addresses and you go with 6 of them into Monero with own Bitcoin and own Monero node via a decentral exchange and obfuscated IP and if you later on avoid co-spending any monero-ed address with one of the other 4 (including their children, grand children etc) then it's really difficult to trace you. But the weak point is that humans get lazy over time and the chance isn't low that you co-spend the wrong coins and then the obfuscations were a waste of time ....
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Board Bitcoin Discussion
Re: Sextortion - more than 4000 BTC cashed
by
BTCtester.com
on 06/06/2021, 21:35:21 UTC
But if you use a coin switching service that doesn't require KYC and you switch into Monero and from the provided address send it to another Monero address, it's over. There is no single way in the world to trace down transactions on the Monero blockchain, at least not from what we know to date.

No. While you're right that highly sophisticated transaction and mixing protocols like Monero or (Coinjoin..)mixers cannot be traced directly it can be done in the most cases indirectly. Successful scammers have to manage earlier or later a high number of addresses. E.g. if someone is doing 500 transactions and is only once or twice co-spending the wrong coins (e.g. unmixed with mixed or monero-forth-back-exchanged coins) then the house of cards collapses often.
I was able to link for this reason more than 20% of a Wasabi mixing transaction outputs to their inputs. If you think 20% is not so much then this was the success rate per single transaction. If people are doing hundreds of transactions then only a low % of scammers are able to stay untraceable over time.
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Board Bitcoin Discussion
Re: Sextortion - more than 4000 BTC cashed
by
BTCtester.com
on 26/05/2021, 22:27:59 UTC
I think the Police worldwide are not really super advance to track the slander. Wallet address can simply be track once the owner is just like us a simple person. But it the owner is knowledgeable in crypto and know deeper than the Police. They cannot track and couldn't give justice to the victim. I hope one day there will have full protection not just for them but also for us who experienced hundreds of scams.

This is the good part for the victims. There is no hurry to catch the scammer immediately when cashing out. The blockchain data are written in stome and the analysis can even be done in years from now. A little mistake in one of 1000 transactions and the house of cards collapse for the scammer.
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Board Bitcoin Discussion
Re: Sextortion - more than 4000 BTC cashed
by
BTCtester.com
on 25/05/2021, 23:10:52 UTC
How about putting the source of the story, I like to check the full details.

4000 is too big, I check the address used and it's just less than 1 btc, so where are the others going?

https://www.blockchain.com/btc/address/1GYNGZLEUGkkQjHo19dHDnGE87WsAiGLLB

Somewhere in the middle of this page I found the BTC addresss and email:
https://krebsonsecurity.com/2018/07/sextortion-scam-uses-recipients-hacked-passwords/

Here you see that the scammer consolidated the 11 successful frauds on the 1GYN.. address into address 1JsACYBoRCYkz7DSgyKurMyibbmHwcHbPd which received more than 4000 BTC in thousands of previous transactions. Thescammer used many different addresses.
https://www.blockchain.com/btc/tx/9d7208192348171c9beb1bede3b7f610ab1811c464fb9cb57891a9f4ad647a9e
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Board Bitcoin Discussion
Re: Sextortion - more than 4000 BTC cashed
by
BTCtester.com
on 23/05/2021, 16:43:30 UTC

It's extremely difficult to track the owner of a particular wallet. Even though it's not impossible. This difficulty in tracing can be amplified through the use of bitcoin mixers. That's the reason why cyber criminals around the world uses cryptocurrency only. Take example from the recent attack on an American pipeline.

There are many ways to cash out such illegally obtained bitcoins. They can use bitcoin mixers to hide the trail of bitcoins and the sell off in any p2p marketplaces. Bot all p2p marketplaces require kyc until you reach a certain volume. There are darknet markets are well. It's unfortunate that bitcoin is actually empowering these miscreants.

It's not so difficult but the police has no time and the victim think it's not possible so they don't try. Such a scammer is involved in thousands of transactions and only one little mistake and the analytics software will catch him. If not now then somewhere in future. So ne scammer can sleep calm. The scammers brain may be think two or three steps depp  in the blockchain but the software finds far deeper connections. Mixers and Monero forth and back might help but the scammers get lost in the high number of addresses to administrate and co-spend coins after mixing with other ones and the house of cards collapses. I was able to linkmore than 20% of a  Wasabi Coinjoin trnasaction outputs to their inputs because of this users mistake. And this doesn't mean for 80% it works. It means if the scammer is doing 1000 transactions and fails on one then he will be caught earlier or later if the loss is not too low.
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Board Bitcoin Discussion
Re: Sextortion - more than 4000 BTC cashed
by
BTCtester.com
on 23/05/2021, 16:35:30 UTC
They can make multiple account and withdraw less than 2 BTC from each account. Simple. And the police do have experts, they just don't fucking care.

Yes they could, but even then Binance is monitoring meta data like screen resolution, Operating and browser system and version etc. and would recognize it. In this specific case the scammer did transactions above the 2BTC limit however.
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Board Bitcoin Discussion
Re: Sextortion - more than 4000 BTC cashed
by
BTCtester.com
on 22/05/2021, 12:00:06 UTC
He is not the brightest but also not the dumbest because the Binance limit with only email verification is 2 Bitcoin per day withdraw.The address has not received more than one bitcoin but even if it did,the guy using a fake email address can withdraw 2 Bitcoins every day and I think with today price 2 Bitcoin everyday is enough even for the hungriest money criminal in the world.We all know that is difficult to track Bitcoin transactions and this is already been discussed here with 0 people being arrested from the cloud mining scams that we all know about.

The scammer was often above the 2BTC threshold of binance, the deposit address is 1JsACYBoRCYkz7DSgyKurMyibbmHwcHbPd and here binance routed more than 16 BTC from this address into their cold wallet:
https://www.blockchain.com/btc/tx/1a8bcc70904a76a09c06a62f9aa2c6ad3e2846bc1898db7a334e69485a87374f