Author

Topic: I think I lost all my BTC with electrum (Read 452 times)

legendary
Activity: 2870
Merit: 7490
Crypto Swap Exchange
December 28, 2018, 03:34:40 PM
#20
Can some expert here let us newbies know how something like this could have been avoided? Would it be to do a PGP check on every electrum download we make? Is that sufficient to prevent this from happening?

Yes that's right. Also don't download from random git repos! Bookmark the electrum website electrum.org and always use that bookmark when downloading electrum. Also always verify the gpg sig.

Additionally you can check the number of repository status (watch, star, fork, commit, etc.), if the number is pretty low, most likely it's not real repository.
legendary
Activity: 3682
Merit: 1580
December 28, 2018, 12:56:07 AM
#19
Can some expert here let us newbies know how something like this could have been avoided? Would it be to do a PGP check on every electrum download we make? Is that sufficient to prevent this from happening?

Yes that's right. Also don't download from random git repos! Bookmark the electrum website electrum.org and always use that bookmark when downloading electrum. Also always verify the gpg sig.
jr. member
Activity: 49
Merit: 23
December 27, 2018, 09:43:49 PM
#18

It's part of Electrum's design. Anyone can run an Electrum Server and put it forward for the public to use. When you run the client, you connect to a random Electrum server (run by some random person), send them a list of your addresses, and they send you back the transactions associated with those addresses. (More-or-less.) This is less secure than running your own full node for various reasons, and it's also terrible for privacy, since some random person gets a list of every Bitcoin address you've ever used along with your IP address. But if you want to avoid these sorts of tradeoffs, then you have to run your own full node, which takes a bit of time and resources.

You might suggest that clients should only connect to a fixed set of trusted and well-vetted Electrum servers, but that introduces fundamental centralization into Electrum's operation, which the Electrum developers wished to avoid. This attack, where an attacker creates hundreds/thousands of legitimate-looking network nodes all controlled by him, is called a Sybil attack, and is a common issue in decentralized systems.

Wow, many thanks for the information theymos. Is there a good place to learn the stuff you mentioned? For example, common attacks in decentralized systems and how to guard against them like running a full node?

Am new to this and so would like to read up more so as not to get scammed. thank you.
administrator
Activity: 5222
Merit: 13032
December 27, 2018, 09:34:06 PM
#17
Thanks both. But can someone explain how it was possible for the attackers to "Attacker added tens of malicious servers to the Electrum wallet network"? This seems to be where the problem started based on this article (https://www.zdnet.com/article/users-report-losing-bitcoin-in-clever-hack-of-electrum-wallets/)

Was this due to a flaw in Electrum? If so, could any of the methods suggested by you both have prevented this?

It's part of Electrum's design. Anyone can run an Electrum Server and put it forward for the public to use. When you run the client, you connect to a random Electrum server (run by some random person), send them a list of your addresses, and they send you back the transactions associated with those addresses. (More-or-less.) This is less secure than running your own full node for various reasons, and it's also terrible for privacy, since some random person gets a list of every Bitcoin address you've ever used along with your IP address. But if you want to avoid these sorts of tradeoffs, then you have to run your own full node, which takes a bit of time and resources.

You might suggest that clients should only connect to a fixed set of trusted and well-vetted Electrum servers, but that introduces fundamental centralization into Electrum's operation, which the Electrum developers wished to avoid. This attack, where an attacker creates hundreds/thousands of legitimate-looking network nodes all controlled by him, is called a Sybil attack, and is a common issue in decentralized systems.
jr. member
Activity: 49
Merit: 23
December 27, 2018, 08:59:26 PM
#16
Not an expert, but here are my 2 cents.

1. Always make sure you download executables from the official websites, and always keep an eye on the URL, and preferably keep the official URLs bookmarked!
2. Be aware of how things work. Take some time out to understand them better, because a little care and knowledge goes a really long way.
3. Make sure you check for any ambiguities. For example, the malicious executable is being distributed as Electrum 3.4.1, whereas on launch, it shows Electrum 3.2.3. Official binaries are always free of such mistakes.
4. Although this is easier said than done, try to be technically sound.

- Electrum is a low-security wallet in general. It focuses on bleeding-edge features and usability, not absolute security. Store only pocket change there (and on the same computer as Electrum). For storing large amounts, use a hardware wallet.
 - The fact that this phishing message was prefixed by "error: error sending transaction" should make one immediately suspicious. If you feel any suspicion about anything, stop and discuss it on the forum or elsewhere.
 - When a new update comes out, wait a week or two before installing it. If it's listed as critical, look at various sites such as bitcointalk.org to figure out why it's critical. If in doubt about whether a "critical" update is real, you can just stop using Electrum for a few days and wait for further news.
 - Navigate to the site using a bookmark if possible, and use HTTPS.
 - Verify the PGP signature when you download it.
 - When you run the executable on platforms that support digital signing, make sure that it's signed by "Electrum Technologies GmbH"

Thanks both. But can someone explain how it was possible for the attackers to "Attacker added tens of malicious servers to the Electrum wallet network"? This seems to be where the problem started based on this article (https://www.zdnet.com/article/users-report-losing-bitcoin-in-clever-hack-of-electrum-wallets/)

Was this due to a flaw in Electrum? If so, could any of the methods suggested by you both have prevented this?

Thanks once again!
sr. member
Activity: 938
Merit: 452
Check your coin privilege
December 27, 2018, 03:28:23 PM
#15

From what I understand after reading relevant threads, intercepting transactions definitely isn't their primary motive. It is to steal bitcoin. They did not have to change things a lot, they just tried do get the users to download the malicious releases (since electrum is open source). They advertised their malicious releases by setting up malicious electrum servers, which probably aren't very different from a normal electrum server, but do show up this message (probably using RPC, please correct me if I'm wrong here). When a person connects to the malicious server, the ad shows up and by clicking on it the user ends up on the GitHub repo containing the malicious code and releases, which has presently been taken down though. Once the user puts in his password, the malicious application gets access to the wallet file, decrypts it using the entered password, and sweeps the coins.

You're right about most what you said, but it's not every time a node connects, that would be too much noise intercepted from them. Every time a client using electrum sends a tx to their compromised servers, instead of them broadcasting it to more nodes like an honest node, they just answer with a fake "Error sending tx" message, and try to redirect them to downloading their malware.

They uploaded it on github under "electrum-project" and "electrum-wallet" (which are thankfully both taken down now).

The part about the application automatically sweeping the coins is what I was talking about, is that really what happened? From what I understood from the comments up here is that they're taking time to sweep them manually, since each compromised wallet doesn't get emptied instantly.. Which is ironic and displays just how little this person's (or more) knowledge was to be able to pull this off... He only intercepts the RPC, sends back his error message, waits for the client to download his malware, and receives the seed so that he can manually spend the coins.
newbie
Activity: 10
Merit: 10
December 27, 2018, 03:26:24 PM
#14
Just a word of advice. This happened to me last night.

FORGET ABOUT THE PHISHED WALLET ...I was experimenting last night with small amounts after the original phishing and everytime I left any amount of coin in it, it would get moved again. This was after all eletrum files were wiped and I restored from seed.

Once you use the malicious client they have access to either your password and/or your seed.

I am in the process of reformatting my drive and doing a clean install for safe measure. This is on a mac.


So just consider the phished wallet compromised from here on.
administrator
Activity: 5222
Merit: 13032
December 27, 2018, 01:27:00 PM
#13
Can some expert here let us newbies know how something like this could have been avoided? Would it be to do a PGP check on every electrum download we make? Is that sufficient to prevent this from happening?

 - Electrum is a low-security wallet in general. It focuses on bleeding-edge features and usability, not absolute security. Store only pocket change there (and on the same computer as Electrum). For storing large amounts, use a hardware wallet.
 - The fact that this phishing message was prefixed by "error: error sending transaction" should make one immediately suspicious. If you feel any suspicion about anything, stop and discuss it on the forum or elsewhere.
 - When a new update comes out, wait a week or two before installing it. If it's listed as critical, look at various sites such as bitcointalk.org to figure out why it's critical. If in doubt about whether a "critical" update is real, you can just stop using Electrum for a few days and wait for further news.
 - Navigate to the site using a bookmark if possible, and use HTTPS.
 - Verify the PGP signature when you download it.
 - When you run the executable on platforms that support digital signing, make sure that it's signed by "Electrum Technologies GmbH"
legendary
Activity: 1246
Merit: 1029
December 27, 2018, 01:26:12 PM
#12
Can some expert here let us newbies know how something like this could have been avoided? Would it be to do a PGP check on every electrum download we make? Is that sufficient to prevent this from happening?

Not an expert, but here are my 2 cents.

1. Always make sure you download executables from the official websites, and always keep an eye on the URL, and preferably keep the official URLs bookmarked!
2. Be aware of how things work. Take some time out to understand them better, because a little care and knowledge goes a really long way.
3. Make sure you check for any ambiguities. For example, the malicious executable is being distributed as Electrum 3.4.1, whereas on launch, it shows Electrum 3.2.3. Official binaries are always free of such mistakes.
4. Although this is easier said than done, try to be technically sound.
jr. member
Activity: 49
Merit: 23
December 27, 2018, 01:07:55 PM
#11
Can some expert here let us newbies know how something like this could have been avoided? Would it be to do a PGP check on every electrum download we make? Is that sufficient to prevent this from happening?
legendary
Activity: 1246
Merit: 1029
December 27, 2018, 12:39:43 PM
#10
Good thing theymos modified the forum header to include this vulnerability and warn people. I was going to make a post myself once I saw the news this morning but I figured it would just be redundant.

Ironic how the people behind this could intercept txes and respond with custom messages but still couldn't get to code software that automatically transfers funds once the wallet is compromised. I hope this doesn't do too much damage, I'm an electrum user myself and really like the wallet..

From what I understand after reading relevant threads, intercepting transactions definitely isn't their primary motive. It is to steal bitcoin. They did not have to change things a lot, they just tried do get the users to download the malicious releases (since electrum is open source). They advertised their malicious releases by setting up malicious electrum servers, which probably aren't very different from a normal electrum server, but do show up this message (probably using RPC, please correct me if I'm wrong here). When a person connects to the malicious server, the ad shows up and by clicking on it the user ends up on the GitHub repo containing the malicious code and releases, which has presently been taken down though. Once the user puts in his password, the malicious application gets access to the wallet file, decrypts it using the entered password, and sweeps the coins.
sr. member
Activity: 938
Merit: 452
Check your coin privilege
December 27, 2018, 11:35:32 AM
#9
Most importantly
1. Do not enter your wallet password on your PC whatsoever.
2. Get a different PC, preferably with a clean OS installed.

In case you have backed up your seed:
3. Create a new wallet and move your funds from your present wallet to the new wallet.

In case you do not have your seed backed up:
3. Locate electrum's wallet file, which is encrypted using your password. Read the instructions here to know where to find it, depending upon your OS.
4. Secure the wallet file and take it to a different PC.
5. Install electrum from the genuine website (https://electrum.org), and open the wallet file with your password and move the funds ASAP.

The attackers are moving funds real fast (based on a comment on the GitHub issue), so act real quick!

Good thing theymos modified the forum header to include this vulnerability and warn people. I was going to make a post myself once I saw the news this morning but I figured it would just be redundant.

Ironic how the people behind this could intercept txes and respond with custom messages but still couldn't get to code software that automatically transfers funds once the wallet is compromised. I hope this doesn't do too much damage, I'm an electrum user myself and really like the wallet..
legendary
Activity: 1246
Merit: 1029
December 27, 2018, 11:22:40 AM
#8
I tried to make a transaction. Was told I need to update inorder to make this transaction. After I updated. I kept getting a error stating " Your fee is too high...etc." I kept trying to send to different peers. Did not work. So I tried to reinstall. but all my funds are stuck in the new update. I looked for the new update browsing through my search history and this came up.

https://github.com/electrum-project/electrum/releases/tag/3.4.1

how can i get my btc back?

Most importantly
1. Do not enter your wallet password on your PC whatsoever.
2. Get a different PC, preferably with a clean OS installed.

In case you have backed up your seed:
3. Create a new wallet and move your funds from your present wallet to the new wallet.

In case you do not have your seed backed up:
3. Locate electrum's wallet file, which is encrypted using your password. Read the instructions here to know where to find it, depending upon your OS.
4. Secure the wallet file and take it to a different PC.
5. Install electrum from the genuine website (https://electrum.org), and open the wallet file with your password and move the funds ASAP.

The attackers are moving funds real fast (based on a comment on the GitHub issue), so act real quick!
hero member
Activity: 1106
Merit: 521
December 27, 2018, 09:23:24 AM
#7
Im on mac. dont know how to completely uninstall. im having my trusted friend install it and use my seed. hoping to get them back. how can i get a new one ? new to this sorry. Also do I need to wipe my mac completely ?

I'm not so sure what exactly the security complications are either. I'm getting a bit confused, so let's make some things clear.


1. You received a popup that looked like this;


2. You clicked the link in the popup and downloaded the wallet from the github.

3. You ran the wallet/imported your seed in the wallet you downloaded, correct?


If the above is more or less what happend, you should indeed let your friend recover your seed, ASAP, as your funds are probably compromised.

Quote
how can i get a new one ?

He should make a NEW electrum wallet on his device, and send a transaction totalling all the funds from the (potentially) compromised seed to the new wallet he just created.


Quote
Also do I need to wipe my mac completely ?
As i said. i'm not entirely sure what has been infected/affected either. Might want to keep an eye on this thread to see what might be smart; https://bitcointalksearch.org/topic/there-has-been-an-increased-number-of-fake-electrums-out-there-be-careful-5089963



May also want your friend to put a larger fee on the transaction to make sure it gets in a block 1st........
legendary
Activity: 1946
Merit: 1427
December 27, 2018, 09:06:18 AM
#6
Im on mac. dont know how to completely uninstall. im having my trusted friend install it and use my seed. hoping to get them back. how can i get a new one ? new to this sorry. Also do I need to wipe my mac completely ?

I'm not so sure what exactly the security complications are either. I'm getting a bit confused, so let's make some things clear.


1. You received a popup that looked like this;

ref: https://bitcointalksearch.org/topic/there-has-been-an-increased-number-of-fake-electrums-out-there-be-careful-5089963
2. You clicked the link in the popup and downloaded the wallet from the github.

3. You ran the wallet/imported your seed in the wallet you downloaded, correct?


If the above is more or less what happend, you should indeed let your friend recover your seed, ASAP, as your funds are probably compromised.

Quote
how can i get a new one ?

He should make a NEW electrum wallet on his device, and send a transaction totalling all the funds from the (potentially) compromised seed to the new wallet he just created.


Quote
Also do I need to wipe my mac completely ?
As i said. i'm not entirely sure what has been infected/affected either. Might want to keep an eye on this thread to see what might be smart; https://bitcointalksearch.org/topic/there-has-been-an-increased-number-of-fake-electrums-out-there-be-careful-5089963

newbie
Activity: 3
Merit: 0
December 27, 2018, 08:58:39 AM
#5
Im on mac. dont know how to completely uninstall. im having my trusted friend install it and use my seed. hoping to get them back. how can i get a new one ? new to this sorry. Also do I need to wipe my mac completely ?
legendary
Activity: 1946
Merit: 1427
December 27, 2018, 08:53:13 AM
#4
Did you actually install the hacked version of electrum - the one you linked to in your OP?

everytime I install the electrum from the website the wizard wont install. itll just take me to the wallet asking for a password

Hmmm, that's weird. Could it be because you still have the other version(s) installed? Try deleting/uninstalling it completely?



Or temporarily use another device?

Another user from the thread i linked above said the following:
When you download the fake client they must get your seed/password somehow. I wiped electrum files then restore the wallet from seed and put 2$ in there an let it sit. They just emptied the wallet again about 30 mintues ago.

It might be smart to hasten a bit.
newbie
Activity: 3
Merit: 0
December 27, 2018, 08:47:03 AM
#3
everytime I install the electrum from the website the wizard wont install. itll just take me to the wallet asking for a password
legendary
Activity: 1946
Merit: 1427
December 27, 2018, 08:28:30 AM
#2
I'm afraid you can't. - If the attacker hasn't moved your funds yet, you might have a chance still.

It seems more than likely you (unfortunately) got phished due to a malicious server.

Read: https://bitcointalksearch.org/topic/electrum-vulnerability-allows-arbitrary-messages-phishing-5090097
And: https://bitcointalksearch.org/topic/there-has-been-an-increased-number-of-fake-electrums-out-there-be-careful-5089963

The link you posted: github.com/electrum-project/electrum/releases/tag/3.4.1 is probably that of a "hacked" version of a electrum.
                            ^ do not use this.


So I tried to reinstall. but all my funds are stuck in the new update.

what exactly do you mean by stuck? Has the attacker sent a tx yet?


IF YOU STILL HAVE YOUR PRIVATE KEYS/SEED, DOWNLOAD ELECTRUM FROM HERE, https://electrum.org/ IMPORT YOUR SEED/PRIVATE KEYS AND MOVE YOUR FUNDS ASAP.
newbie
Activity: 3
Merit: 0
December 27, 2018, 08:21:52 AM
#1
I tried to make a transaction. Was told I need to update inorder to make this transaction. After I updated. I kept getting a error stating " Your fee is too high...etc." I kept trying to send to different peers. Did not work. So I tried to reinstall. but all my funds are stuck in the new update. I looked for the new update browsing through my search history and this came up.

https://github.com/electrum-project/electrum/releases/tag/3.4.1

how can i get my btc back?
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