They have stolen bitcoins from my official Bitcoin wallet

[shorena]

first of all i am sorry for the lost. but did anybody here asked op to sign a message to prove the ownership of the address? it's important right to claim that the address is really owned by op. and after that we can go discussing this . no offense op okay 

No, why? They can hardly reclaim the coins with a signed message. I dont see how that matters at all.

I think he means to say that we should first actually get some proof that OP's wallet was indeed hacked and he is not just wasting everyone's time with wild speculation as to how his wallet might've been hacked

I've not understood you pretty well. English is not my native language

Its not important I think. Just someone wants you to proof that you have been stolen. E.g. with a signed message -> https://bitcointalk.org/index.php?topic=990345.0

How did you store the password?

[calkob]

really sorry to hear these stories, i myself have lost bitcoins to theives and it is gutting, keep the chin up mate.   would love to know who you believe they are?  and also in the futre my dont keep all you bitcoin at one address, and with a haul that size it should def be in cold storage.

all the best

[Amph]

I've made clean installation of Windows 2-3 times since I've entered the passwords last time.
I hope the  investigation of this case can improve the Bitcoin world and can prevent such incidents in future

there are some nasty bios virus, that cannot be removed with a simple format c/secure erase, they are rare, yes, but it may be your case

basically your pc is still infected no matter what you do, unless you change the motherboard

[gkv9]

It ain't just limited to desktop based wallets guys...
Even I am seeing some login attempts in my blockchain.info account that I currently have...
I don't know who the hell tries to attempt to login in my account there, but I get a code from Blockchain everyday because I have enabled 2-Factor Authentication...

So, beware these days guys, there ain't anything called "SAFE" in terms of wallets for bitcoins...
The only best thing I believe are paper wallets...

[shorena]

It ain't just limited to desktop based wallets guys...
Even I am seeing some login attempts in my blockchain.info account that I currently have...
I don't know who the hell tries to attempt to login in my account there, but I get a code from Blockchain everyday because I have enabled 2-Factor Authentication...

So, beware these days guys, there ain't anything called "SAFE" in terms of wallets for bitcoins...
The only best thing I believe are paper wallets...

Sounds like your wallet identifier leaked. Lets try to stay on topic though, shall we?

[ed_war_d]

It ain't just limited to desktop based wallets guys...
Even I am seeing some login attempts in my blockchain.info account that I currently have...
I don't know who the hell tries to attempt to login in my account there, but I get a code from Blockchain everyday because I have enabled 2-Factor Authentication...

So, beware these days guys, there ain't anything called "SAFE" in terms of wallets for bitcoins...
The only best thing I believe are paper wallets...

Sounds like your wallet identifier leaked. Lets try to stay on topic though, shall we?

The wallet is from the official website

[ed_war_d]

really sorry to hear these stories, i myself have lost bitcoins to theives and it is gutting, keep the chin up mate.   would love to know who you believe they are?  and also in the futre my dont keep all you bitcoin at one address, and with a haul that size it should def be in cold storage.

all the best

I've splitted them to 2 different wallet on 2 different computers

[zivone]

31 BTC, oh my... I would go crazy if that would be me. Technology is getting better and better but  the other way around for the security of the users.

[RodeoX]

With Bitcoin you are the boss! That not only means you are in charge, but that you must work. Bitcoin security is no better than your security. If used correctly it is miles above the bank's security system. However if you do not protect your private key then no other methods matter.  

I don't know how this happened to you, but someone must have gotten that key. Consider who else has access to your computer. Think about where you store your private key. This breach may not involve malware at all. Also, Think about a more secure OS like Linux.

Sorry to hear about your loss.  

[ed_war_d]

With Bitcoin you are the boss! That not only means you are in charge, but that you must work. Bitcoin security is no better than your security. If used correctly it is miles above the bank's security system. However if you do not protect your private key then no other methods matter.  

I don't know how this happened to you, but someone must have gotten that key. Consider who else has access to your computer. Think about where you store your private key. This breach may not involve malware at all. Also, Think about a more secure OS like Linux.

Sorry to hear about your loss.  

Look at the picture from my 2nd wallet:
http://tinypic.com/r/ddsw0/9
There is no address in transaction. The label "нeдocтyпнo" means "no acsess"
It seems it's pretty strange

[cr1776]

...
I've made clean installation of Windows 2-3 times since I've entered the passwords last time.
I hope the  investigation of this case can improve the Bitcoin world and can prevent such incidents in future

The isn't a bitcoin issue, this is a computer security issue.  If you can't secure the computer, nothing that the bitcoin developers do will help stop it.

If you can't secure Windows, use Linux or OS X or any number of other OSs.  And use them ONLY offline.  Or use a paper wallet.  Or a hardware wallet. 

Sorry for the loss.

[johnyj]

Possibly a password theft if your password is too easy to guess (several words you always use) but in order to steal your coins, the hacker must also have access to your private key. In fact there is no 100% sure way to make sure that no one else have your private key unless it is generated by you manually and kept offline secretly

The entropy in core client should be strong enough to avoid key collision, but the key should be generated offline and kept offline most of the time

[ed_war_d]

Possibly a password theft if your password is too easy to guess (several words you always use) but in order to steal your coins, the hacker must also have access to your private key. In fact there is no 100% sure way to make sure that no one else have your private key unless it is generated by you manually and kept offline secretly

The entropy in core client should be strong enough to avoid key collision, but the key should be generated offline and kept offline most of the time

The passwords were about 30 simbols and didn't contain whole words
I've never entered the passwords for many mounthes

[ed_war_d]

first of all i am sorry for the lost. but did anybody here asked op to sign a message to prove the ownership of the address? it's important right to claim that the address is really owned by op. and after that we can go discussing this . no offense op okay 

No, why? They can hardly reclaim the coins with a signed message. I dont see how that matters at all.

I think he means to say that we should first actually get some proof that OP's wallet was indeed hacked and he is not just wasting everyone's time with wild speculation as to how his wallet might've been hacked

What proofs you would like to get?

[johnyj]

Possibly a password theft if your password is too easy to guess (several words you always use) but in order to steal your coins, the hacker must also have access to your private key. In fact there is no 100% sure way to make sure that no one else have your private key unless it is generated by you manually and kept offline secretly

The entropy in core client should be strong enough to avoid key collision, but the key should be generated offline and kept offline most of the time

The passwords were about 30 simbols and didn't contain whole words
I've never entered the passwords for many mounthes

It is possible that your private key is already stolen before you set the password. For example, some Trojan has been installed before you install the core client, and they constantly searching for the wallet.dat file on your c drive. Once found, they immediately send the wallet to the hacker, and that is before you even set the password

[ed_war_d]

Possibly a password theft if your password is too easy to guess (several words you always use) but in order to steal your coins, the hacker must also have access to your private key. In fact there is no 100% sure way to make sure that no one else have your private key unless it is generated by you manually and kept offline secretly

The entropy in core client should be strong enough to avoid key collision, but the key should be generated offline and kept offline most of the time

The passwords were about 30 simbols and didn't contain whole words
I've never entered the passwords for many mounthes

It is possible that your private key is already stolen before you set the password. For example, some Trojan has been installed before you install the core client, and they constantly searching for the wallet.dat file on your c drive. Once found, they immediately send the wallet to the hacker, and that is before you even set the password

In this case why they didn't steal it 3  years ago?

[Xialla]

I installed Windows 10 in October.

so, this is your problem. sorry for your loss..

[RodeoX]

With Bitcoin you are the boss! That not only means you are in charge, but that you must work. Bitcoin security is no better than your security. If used correctly it is miles above the bank's security system. However if you do not protect your private key then no other methods matter.  

I don't know how this happened to you, but someone must have gotten that key. Consider who else has access to your computer. Think about where you store your private key. This breach may not involve malware at all. Also, Think about a more secure OS like Linux.

Sorry to hear about your loss.  

Look at the picture from my 2nd wallet:
http://tinypic.com/r/ddsw0/9
There is no address in transaction. The label "нeдocтyпнo" means "no acsess"
It seems it's pretty strange

No information about the transaction? That is strange. You did a lot of things right, using the long password with no words. That rules out guessing your password. You are using good anti-malware. That makes malware a little less likely.
If you wrote the password in a document or on a slip of paper you may want to check the security on that document. It may also be worth asking yourself "who else knows I have bitcoins and has access to this computer"?
What a bummer. Can blockchain.info give you a Tx ID? That may give some more information.  

[Hannu]

They have stolen bitcoins from my official Bitcoin wallet.
Wallet had the password (about 30 characters)
Last time I've entered the password at least 6 months ago.
I installed Windows 10 in October.
Kaspersky Internet Security says no viruses.
https://blockchain.info/address/15ESHhWuNfqMEQPXWexGb9kK1J53brWksL
What do you think thinks about this? The system is so full of holes?

(Russian version is here:
https://bitcointalk.org/index.php?topic=1278586.0  )

Do not use windows 10... We have been problems example in working place with windows 10   -Normal use like infra etc
If you must use windows 10, install all updates what it offers to install.  
I tried to use bitcoin core win10, i went to workplace to home Hybrid Kernel has been collapsed totally and file system!

First aid to computer: https://www.f-secure.com/fi_FI/web/home_fi/online-scanner -Proud to be Finnish   
http://www.surfright.nl/en/hitmanpro

[cr1776]

With Bitcoin you are the boss! That not only means you are in charge, but that you must work. Bitcoin security is no better than your security. If used correctly it is miles above the bank's security system. However if you do not protect your private key then no other methods matter.  

I don't know how this happened to you, but someone must have gotten that key. Consider who else has access to your computer. Think about where you store your private key. This breach may not involve malware at all. Also, Think about a more secure OS like Linux.

Sorry to hear about your loss.  

Look at the picture from my 2nd wallet:
http://tinypic.com/r/ddsw0/9
There is no address in transaction. The label "нeдocтyпнo" means "no acsess"
It seems it's pretty strange

No information about the transaction? That is strange. You did a lot of things right, using the long password with no words. That rules out guessing your password. You are using good anti-malware. That makes malware a little less likely.
If you wrote the password in a document or on a slip of paper you may want to check the security on that document. It may also be worth asking yourself "who else knows I have bitcoins and has access to this computer"?
What a bummer. Can blockchain.info give you a Tx ID? That may give some more information.  

I think it was this in the first message:

https://blockchain.info/address/15ESHhWuNfqMEQPXWexGb9kK1J53brWksL