For several years I used Mycelium wallet to work with quite large BTC amounts, though I used the HD-account for small BTC amounts, and operated large amounts by adding SD-accounts from piper wallets.
December 10, 2017 I've installed Mycelium wallet to Xiaomi Redmi 4A with unrooted unmodifyed latest stock ROM, and made a backup of 12 words, installed a PIN code, then
transfer ~1 BTC to the first address
13w2xGFYACssGMWhMsDueua6hwyMZ4CWBR of the new HD-account.
Once the child accidentally deleted Mycelium from the phone — but I was not worried much — I've got a 12-word backup!
February 18, 2018 I decided to restore Mycelium wallet, so enter 12 words and what was my surprise when I saw a new empty HD-account, with one private address key [
12phYenkBswojQXFvkz8NQrmixYAP4pcWx]! I wrote about this to Mycelium support creating an issue
#8931, they responded promptly the same day:
Alyona Gomozova
Hello! We have a suspicious you made a wrong backup. Could you send us your Public key, please to see clearly how can we help you next.
You can do it that way: go into Mycelium app > Accounts tab > long tap on your account > click 3 dots in the right upper corner > choose export > copy the Public key
Have a nice day!
I've sent the requested public key of the HD-account: [
xpub6BoY4wywjSo22AWFBtZsQZEEx6AXXXeLbybKZwZUzJoAThegPECiCEuFcycnf9wsV1seZ1Z2gik hZ3MVCbMGoubRbB9iaRzSpk2EvBvQQNn] waiting for answer ...
February 22, 2018 I've asked support about any news on my issue —
there is no reply!February 25, 2018 came to visit a friend, he had an iPhone, I asked to give it to me for an hour for experiments. I downloaded Mycelium from AppleStore then recovered the account from the 12-word backup and what do I see?
New empty HD-account anyway [
xpub6CGzV2tBAWvWoV732vVndwQHmur5mbqhTFGASs8TEGBqZptpsCuJgTHPP4uCiVqCLGdyA4SEVdx q4zadvs6UyX2ZzayPYJ5dVgZLn5XQic]!
I've deleted Mycelium from iPhone and wrote to Mycelium support, with a reasonable question: how does it happen that one 12-word backup restores different empty HD-accounts, and how to reach the initial account to get access to my coins?
There is no reply again.March 08, 2018 I've decided to try to restore the HD-account from backup again, so the other day noticed that Mycelium was updated in Google Play ... The HD account was restored, but
0.99 BTC was lost! This is the
transaction. It is noteworthy that the return was sent to the address [
1HmoGNVsuSwA4bbAqXYFzJaUm796yjpi7k] — this is the next address of my HD-account! Why it happens so — may be to make an illusion the transaction was made by legal Mycelium user? I don't know.
The coins was sent to the address [
33z13D1jDTKNwpHRAJKGKaWw64kdcZF8nV] — there is a zero balance now. It is noteworthy that at the same address later was sent other 0.07 BTC. The incoming coins are almost immediately sent to other p2s-addresses, seems like the client deposits of the exchange
wex.nz — I also write to their support service about a froud activity (but they're did not reply anything).
CONCLUSION: I believe that some people from the Mycelium wallet team stole 0.99 BTC from my HD-account.How can this happen technically? Example scenario:
1) When restoring an HD-account the application requests the Mycelium server for account transactions;
2) If there is a certain BTC amount on the account, the server can send a special response to the application;
3) The application receiving special response sends a private key of the HD-account to the server, then generates new empty HD-account to the user.
This scenario is inspired by the strange behavior of the program restoring the HD-account from the 12-word backup and the deathly silence of the support service suddenly stopped contacting me.
Sorry for Google Translate, my native language is Russian, original post is here.