Bitcoin Forum

I keep seeing all these posts that someone can hack my wallet.  First I did not think that this could be done?  If it can be done, how can I prevent it from happening?  Does my wallet need to be online in order for them to be able to hack it or can they still hack a paper wallet?

Your wallet on your pc or in an exchange is only as safe as your pc  or that exchange.    Your pc could easily be compromised by any keylogger or trojan.   And as far as exchange wallets go, well, Mt. Gox is really all that needs to be said about that.     Paper wallets are safest, however not perfect because they need to be generated usually by your PC.

It is possible that someone can just guess or brute force your private key. The chance however is so small you might as well call it impossible. Its as likely as someone winning the lottery several times in a row and will for all we know never happen as long as the sun is still burning.

Other than that it mostly depends on the way you use your machine. As AllInCrypto said if the machine that you use to control your wallet is infected by malware, its easy for the attacker to spend your coins. Its however not "easy" to infect a modern, well updated system, unless you do something to help the malware. Commonly bitcoin related malware will require you to execute it yourself, so be careful what you download and use.

for about 4 years since i know about bitcoin i never have my own wallet running on my pc i usually using bitcoin wallet address from an exchange or an online wallet like coinbase, after i read much information from here in this forum i have consider to install bitcoin wallet on my pc and running it as my own private wallet and i also using paper wallet that i use it for saving in bitcoin and will never redeem it untill 5 years from now, and my opinion is that wallet on our pc and paper wallet is the safest place to store our bitcoin on there rather than any other kind of wallet

Those hacking method are mostly brute force. You usually encrypt your wallet with a password. If your password is short (less than 8 characters ) it could be cracked by brute force methods. It needs a while, and the hacker needs a computer with lot of power, but it is possible. Especially, if the hackers knows the length and some chars of the password.
To get sure, choose a password of at least 12 characters including letters, numbers and special characters.

Bottom line is if you have a lot of bitcoin that you dont need instant access to then stick it on a paper wallet, if you need to use that bitcoin a lot then considor a hardware wallet, if its just a small amount then just store it on your phone or pc but be carefull with what you download. As far as i know most people arent targeted for specific bitcoin stealing programs unless the attacker knows that you use bitcoin but if you were infected by a trojan then someone would soon find you are using bitcoin.

well... with keylogger they can turn your life to very miserable I have to say because everything you do will be recorded, typing password to unlock wallet, generating wallet paper. The only way to prevent it is scanning your pc often and do not download potential virus software. By doing, you can be considered safe I think

The is way you should use a second PC in order to do your crypto stuff. This computer should never go to the internet. So, you can make sure that are save from keylogger, viruses and other hacking software.

It is next to impossible that someone cracks your bitcoin wallet through brute forcing your private key. The number of keys is so astronomically big, that you are better of buying a lottery ticket.

Hacking is a whole different thing, and mostly relies on stupidity of the users. If you install dubious software or give away sensitive information, you may get hacked.

so it works like a cold storage right? I think we just need a virtual machine or maybe dual boot with an clean OS (nothing got installed at all) and everything will be alright but extra precautions are advised so you might want to use a second PC like tyz said ;D

it's not hack, it's stealing let don't get confused here

bitcoin can not be directly hacked in the sense that the hacker can not steal you funds by brute forcing your public key

but he can steal those if you have an infected machine with a rootkit or whatever

If it is coins you need access to and are actively using I suggest hardware wallet.  They keep the private key off of computer and sign the transaction on the device.  So it is very secure.  If used properly even if infected you are still safe with a good hardware wallet.

Other option is if you are not going to touch them at all look into paper wallet.  You can monitor the address online and send it, just keep private key on paper only.   Again it is if done properly, if not your insecure.

Those are best two options I think.

The most used way by hackers is that they install a keylogger on your computer through software that you have downloaded somewhere. If you login to your wallet, all the keys u clicked will be sent to them, also your password and wallet information. So they login and steal your coins, as easy as that.
Another way would be brute force, to prevent this from happening, you need a strong password with much charachters and special numbers/symbols and uppercase and lowercase. To prevent keylogging, do not download anything fishy or from a non reliable source!

If you have an easy to guess private key, then anybody can hack it from anywhere.

If you have a virused online PC where you keep your wallet, or you have an online web wallet then its also vulnerable.

Always Remember, as long as you have 2FA enabled there will be few little chances of your account being hacked.

Yes your wallet can and will be hacked if you do not take the needed measures. If you are using a web wallet be sure to activate you 2FA security option and always be sure to have a very very strong password for your accounts. if you have a Desktop wallet be careful, don't hold many bitcoin in there.

As for a paper wallet if you follow all the right procedure it is nearly impossible to hack

Don't forget that Microsoft has installed a keylogger in Windows 10.

Wow I'm glad I didn't install 10. Is there at least an option to turn it off?

yes there are some guide, on how to turn off cortina and everything in the privacy windows

but i doubt win 10 will ever steal your private key, it's as good as the best fud out there about the value of bitcoin...

I think it's not about hack, but it must be their relative that hack his/her wallet. i think it's hard to hack someone wallet on online wallet. for prevent this maybe you should make your password hard and only you that know your password.

Wow i don't know that microsoft has installed keylogger in windows 10. Actually it's easy to prevent hacker, don't download something that suspicious and download anti malware and spyware.

I don't think win 10 would try and steal my keys, but at the same time if you have a factory installed keylogger wouldn't that make it easier for a potential hacker to find your information once he is inside your system?

you mean someone malicious from microsoft employees? because another hacker if he install his keylogger it certainly won't benefit too much by the fact that windows 10 has already one...

Fair point, but even in your scenario it still doesn't make me want to have a factory installed keylogger. I can promise you not everyone at microsoft is a saint and people get ripped off all the time by malicious employees.

Haha you mean those microsoft call center scams from India.

Haha those guys might be real microsoft employees, but they are just part-time scammers trying to earn an extra buck :D

Just reading through and have to question how someone could brute force your private key?  I of coarse do not understand what the private key is nor do I understand what brute force means, but the thread interested me.

yeah that's true, i would only store a small amount on windows 10 as it is right now, until they can sort this mess at 100%

better to avoid it and use linux/win 7 for the time being

A private key is just a number. So lets assume the possible numbers for a private key are between 1 and 4. I dont know your private key, but I just test all 4. Thats a brute force attack. I just try all possible combinations and see if I hit the jackpot. Of course with bitcoin the number is significantly bigger. There are 2²⁵⁶ = 115792089237316195423570985008687907853269984665640564039457584007913129639936 possible private keys. Roughly one for every 1000 atoms in the known universe[1]. This makes guessing your private key possible with infinite time and resources. We dont have infinite time and resources though, so we can consider it impossible.

[1] http://www.wolframalpha.com/input/?i=2%5E256

It could be brute forced, but the amount of time it would take to crack it would be ridicules.


I doubt anyone would try unless it was for thousands of bitcoins.

Yes, and the probability that you find it before that is also slim.

Because probably the private key will be in the latter half of the number range, because nobody will put a small number for it like 92532

Hello, xmax! There are really some ways of hacking into your wallet... One of the most widely spread methods is using some keylogger software. There are several free tools available now like the one from Spyrix (http://www.spyrix.com/spyrix-free-keylogger.php). You should be aware of such things because they log all the keystrokes and passwords when installed. I've used some keyloggers for monitoring purposes, so I know how they work :) Just be sure that there is no any suspicious software on your PC and install a good anti-virus

Yes, that is true. Microsoft is gathering telemetry data and know everything you do on your Windows 10. Win 10 has keylogger build in by default, you can however try to disable it by using various 'no spy addons'.
But if you own bitcoin I would not be worried about Microsoft, they won't steal your bitcoins, they just like to spy on you.

so that means Linux and android operating systems are safer than microsoft products
e.g . Microsoft windows 10
thank

As far as I know Microsoft added telemetry spying functionality to their older systems: Vista, 7, 8 via Microsoft Updates are not safe anymore.
Currently probably only Windows XP is free from spying eyes of Microsoft but that is because this system is ancient.
But then again, stop worrying about Microsoft, they are not gonna steal your money. Be sure to not install unknown  software or visit strange sites instead.

I`m not so sure about that, if it's in the shadows, and bitcoin gets big, they can easily steal money, and blame it on hackers. Or one of their rogue employees starts stealing.

Or even if they not, any hacker can just hijack their keylogger systems and steal that way, either way it stinks badly.

that's scary, I bought a new laptop with Windows 10, made my first few paper wallets there :(

I had been quite safe to use wallet Blockchain.info and add security use Google Authenticator (2FA).
if you always play altcoins trading and download a wallet, be careful there is usually some viruses such as keylogger or other dangerous viruses

Yes those keyloggers are worse than anything and you can get it by clicking on links,
also here on this forum we have lot of scammers training to get your account and rob your coins.. >:(

use zemana for simple keylogger, it hide yourkeystroke, pretty convenient

for keylogger that take screen or stuff like that you need soemthing else, but i think the full version of zemana can handle all of them

Can you get malwares and keylogers if you downloading movies via torrents?
Will antivirus react on it?
Someone have experience with this?

Well i don't think it's that much easy to hack someone's wallet, but if it happens then not usually, maybe once in a blue moon you know what i mean.
I never heard someone saying to me that his/her wallet has been hacked, and that proves that it only happens to some people unfortunately.

The important difference is that bitcoin is not hacked (I assume you mean cracked).
There will always be creative deviants who figure out a way to get to some wallets. They may trick you into revealing your private keys or place a keylogger that watches and waits for you to enter a password. Or someone could beat you with a hose until you tell them the password.  :-\

No one can hack a paper wallet, but if you keep your bitcoin at a webite that holds the private keys then yes you could lose the bitcoin.  the bitcoin is not yours unless you hold the private keys......  :)

Its recommended not to use online wallets like blockchain.info because the website has been DDos's by hackers multiple times.You could never know if your funds are totally safe there.Its very tough for the hacker or say impossible to hack a cold storage.If you use bitcoin core or electrum,secure your funds ,keep the private key safe,maybe paper wallet.There are no chances of hacker getting any access to them.Plus you store the keys away from your computer.

Sure, maybe not in a video file, but there might be an executable involved.


Maybe.


No, I havent pirated something in years. It was however common that pirated material had viruses with the files, esp. for programms or games and cracks or key generators for those. Most viruses are made for Windows, but this is changing as Linux and Mac are more and more common.

The only problem is it has to be done right.  Say you use a newer printer and it's compromised.... you could lose it through there.  Rare yes but not impossible.  The dumber the printer the better, also if you print a wallet might look into how to clear cache on your printer.

Also storage of that paper wallet is key.  Best is stored on a piece of paper in a place such as a bank safty deposit box.  Don't upload it to the clouds or anything or you defeat the entire purpose of it.

If your actively going to be using it look into hardware wallets keeping the signing of transactions on them where eve if computer is compromised your coins should be safe.

i think mycelium wallet in android is much safer , secure and untracable than the desktop wallets

I am not that much in BTC , but I am in technology , I am using other sites with 2FA, you can get burned if you try to setup 2FA in an infected machine. The hacker can see that one time key needed for manual entry to disable your 2FA, so I insist that you do the setup of your 2FA in a PC you are 1000% sure it is not infected with anything.

What is best combination antivirus+spybot?
What else to use?
Windows 7.

For to prevent to hack your wallet i think you need a two factor authentication or sms verification for every login to make sure that you are the only can open your wallet.. or you may try also cold storage of electrum and make sure you save your seed and password and some important thing like default_wallet.dat save anywhere in your computer that you think its safe..

Even SMS verification won't help when the hacker have the private key of yours. He can open that wallet in any PC without any verification at all.

Power it off?

I dont know about you guys but I have a normal printer that prints only. Not with wireless crap and other stuff that has attack vector.

I just power off the printer, and the cache clears, because it doesnt have memory card and things like that.


Wow storing it in a bank, how logical is that.

We all use bitcoin because we dont want to use banks, but theN you say just put the access to the bitcoin wallet into the bank. That makes sense....

Any computer system online could potentially have exploitable weaknesses that could be used to gain access to one BTC and private keys.
Common sense and a decent understanding of how BTC works is a must when dealing with the storage of coins.

All sorts of ways a would be hacker could gain access to a persons Bitcoin, The trick to avoiding this is to be cautious of downloads and keep all private keys backed up in multiple places offline and have them secured by password.

This is mainly for commercially used printers. In which case a power off would not help either, because they use a harddisk for long term storage. AFAIK this is not common on end user printers.

I see, well, dont print out sensitive info with 3rd party printers ever.

There are many shops that offer printing services, but one has to be a fool to print out sentitive data with them.

Only use your own printer (not even your neighbors) to print out sensitive data.

I agree, but I think thats where the fear printers might store the data comes from. If someone uses a printer at home and think it might still have sensetive data on it, they could just destroy the printer once its lifetime ended. I also doubt home use printers will have hard disks as they have next to no need to store a large amount of data and it would only increase the price per device.

These days it very difficult to hack and spend bitcoins in this technology.
Accounts gets hacked only if online wallets are preferred. Now most has
a offline wallet like electrum. So the risk of hacking is found to be very
less. Even it has got various authentication features in online wallets
too which won't be that easy for hackers to enter.

And one day you just enter again your username and pass on web and soon
you realise you can't connect anymore to your account..One small mistake and you won't notice.
Phishing is worst of all i think!

Anything could be hacked, not just bitcoin wallets. Bitcoin wallets are obviously harder to crack than normal passwords since the length is much longer +  the characters are completely random.

If your wallet is online then it'll stand a much higher chance of being hacked, however even offline wallets can be cracked using brute force methods...

You can always check the vendor's site and see what specs the printer have, my printer only has a cache that clears every poweroff (worse case scenario after 2 printings).

So if 1 print out a password, I can then print out a photo aftewards and the cache is overwritten.

I`m not sure why any other printer has hard disks, it has no sense, you can just store the config of the printer on your OS with the printing software that you got with the printer. No need to put separate harddisk in the printer itself.

Its very insecure architecture then,

Im talking about something like this

http://www.clubcopying.co.uk/images/large/canon-ir3225n-ir3235n-ir3245n-copier.jpg

they will store large amounts data and transfer (or recieve them) over a network connection. Sometimes from several users at once and significantly over 100 pages. A harddisk is just a cheap way to store that data. Due to the nature of harddisks the data is available from a long time after it was needed last (unless overwritten).

So its a network printer, well that is absolutely not good, and not secure.

That is a huge and direct attack vector, and possible exploits could exist, where hackers could grab your printers cache and send it to them via internet.

Nope, dont use that folks.

Your wallet can't be hacked, your pc can.
A wallet is totally secured, it would cost billions time more energy to hack it than what there is inside even if you earn thousands of btc.

But your pc can get a trojan installed or a keylogger then someone will access manually to your wallet, but the same way they could (and they will) access your bank accounts in fact.

Think we have more people's stupidity than hacking special abilities..

Hacking is not the good way to have bitcoins you will be in prison if you do that its better to find another skills like making a website seo or service that you can promote a site.. Or join ins signature campaign to earn some bitcoins..

well none is using somethign like that for papaer wallet, we use something more personal more small, like any small canon printer or epson

as long as it's for personal usage, i don't see the issue with the memory cache

This is the high risk that bitcoin is facing. Hacking is very serious issue, even there are hackers who are into teaching users how to hack and get into someones account for certain fixed amount. Once a person gets into it he does it continuously which make him master in it. So to get rid of it using offline wallets are better.

Well, if a user’s account and password got hacked and he/she did not have ‘two factor authentication’, then he/she does not have a strong position to talk to his/her exchange but I think such a user could at least try to do the blockchain analysis

If you're using bitcoin core, I'd recommend encrypting your wallet.dat file with a password, and encrypting your whole wallet with Veracrypt. It might have flaws, but another layer of security will still slow down any attacker.

I simply use the HW.1 Ledger hardware wallet, it's pretty safe.

If you use electrum, with seed as a password , which is a passphrase made up of 13 random words.

Then all you need is a pen and paper, or memorize it. It's easy to write down words.

But if the private key is just random characters, then its bad, that needs to be printed out, to avoid misspelling which could cost you your savings.

but this is not limited to bitcoin, all the online activity that one does is susceptible to hacking. this can be using bitcoin or using your credit card information. there is a lot of stories about stolen credit cards and all the money laundering that robbers do with those information like buying goods with stolen credit card and selling it for cash.

paper wallet is secured to be hacked. if you worried about your online or desktop wallet. than go for a paper wallet.

Be careful with exchanges.  You never know who to trust.  If you use one, don't put much on it.  I lost some bitcoins in Cryptsy.

Hacking is very hard to prevent once they target and focus on yours. The best thing you can do is to split your bitcoin into different addresses you have.

yes it was one of the best ways, do not save all bitcoin on one wallet and also do not forget to always use double security.

That's right, if you are targeted by a hacker then you can't really save yourself forever, he will not leave you if he see much coins in your wallet, better to split them in different wallets and different places, keep some in cold wallets and some in online wallets. You will feel safer that way.

Well i myself never used a paper wallet and i even have no idea about it actually works or how to use one, but it is also safe to split your coins in different wallets because if one get hacked then your other coins will be safe, and try to split them in small parts as you could lose much if any of them get hacked in case.

Spliting coins in different online wallet is a good idea. Also i recommend to use a strong password.
and never share your password with anyone. Most of the time Hacking is done because of our lack of responsibility.
Follow the best principles of Passwords and your wallet will be safe.

Always secure in offline your private keys or backups.

Never trust any other website which hold your BTC 100%, cuase we seen to many times exchanges and many other services going down with all the investor money.

And to reply to your question an hacker could stole your wallet really easy, so at least protect with a good password, so that it will be nearly impossible to break if it is enough resistant.

I think offline is the best to hold bitcoin. Yeah it is true don't trust any website which hold your bitcoins also the online web wallet there's a possibility that the site will be down and they will announce that their website is hacked..
So offline wallet is still the best to hold bitcoins. and secured it. So that you are in far from hackers..

Yes storing in cold wallet is the most secure way. The only disadvantage of using cold wallet is that if you have to do lots of transactions then it takes a lot of time. Otherwise cold wallets are best for savings.

There are also situations where you use a wallet on an exchange that gets hacked so you are relying on their security that was flawed.

If you're serious as fuck about your bitcoins, consider a hardware wallet like trezor. Paper wallets can always be lost or drenched in water (yup, happened to me before). Hardware wallets are pretty strong and have lasted me a year or two. I plan to buy two hardware wallets soon in fact

then don't forget to activate two factors authenticator, and use email or phone confirm to open your online wallet. it will be safer.

store them only for trading and small amount and activate auto withdrawal on your cold storage


another disadvantage is to remember thta the key pool contain only 100 key so if ou keep create new key to receive new funds on your cold storage and forget to do a backup after 100 key your next transaction will be lost when you want to use that back up again

This is a good idea but how much this hardware costs? is it handy and convenient to use? im curious about this bitcoin harware wallet ;)

We cant say that the online wallet which was hacked, its security would be still the same. It maybe possible that they have upgraded their system and now there is no loop hole in the system. Secondly we cant only blame the online wallet security for it. What if we don't keep password difficult and secure, as it should be.

Well its not that easy to know the password of wallet, email and then SMS.
I little carefulness is setting up all these can save our accounts from being hacked.

 yes a paper wallet could be hacked :  the attacker just need the private key, and could obtain it if you dont print it securely.. , of if you generate it online .. you see ?

WTF, drop it in water?

How about making multiple copies of it, perhaps writing it down on a laminated paper with a market to be water proof.

If you keep it on a small note paper somewhere in the house then of course it gets messed up.

I've recently downloaded The Electrum wallet.
And u have the option there to make a double authenticator wallet.
So you always have to double authenticate with your phone.
So if someone wants to steal your Bitcoins, he will need your private key and your phone.
That way someone on the other side of the world cant hack ur wallet.

I agree when you make the paper wallet you should not make 1 print only of it.  It would be crazy if you did to have it in a area with water around it.  When you store safely you would be smart to have at least a copy always stored away.

I do like hardware wallets more and more.  Also 2nd factor devices.  I see these becoming more and more popular in future.  Which is likely a very good thing.