Today when I logged onto Blockchain.info, I noticed the 40+ BTC I had in my wallet were gone and had been sent to this address 1GvmpUY1RdR5zf7jDZnpjfuBnoCz3S2xSS at 12:20am Aug 2nd. I'd appreciate some help to understand what happened, and if possible, how I can get the BTC back. I'm not a tech person, so it's been a struggle to learn what I have about Bitcoin...
Here is the transaction information. https://blockchain.info/tx/3ea2a7343d5623058ac7cc403d82e4fc9a351ef0e8818f1fe0d1b3351e6ad434 Please let me know if there is more information I can provide that would help.
I had previously used a paper wallet, but transferred my money back to Blockchain to enable easier transactions. I was using 2 factor authentication with an SMS code being sent to my phone to be able to access my wallet. I did not notice this at the time, but now that I checked, a wallet authentication code was was sent to my phone at 12:17am Aug 2nd. I do not recall ever seeing this until now.
Thanks in advance for your help.
EDIT: Further info also posted below.
After doing further investigation and digging through old emails, I've learned the following.
When I first signed up to Blockchain, I stupidly emailed myself my Blockchain username, password, mnemonic/security phrase, and wallet address.
Later on Blockchain emailed me an encrypted wallet backup.
After reviewing the IP addresses that have accessed my Gmail (https://security.google.com/settings/security/activity), I noticed one that appeared to access from an iPhone that I did not recognize. It was also a Verizon network iPhone and the IP address was mapped to about 30 minutes outside my city. This was on July 18th (and the theft happened on August 2nd). Potentially also of note, I used public wifi at a hospital on July 30th.
Is this the likely scenario? That my Gmail and/or iPhone was compromised? And would this explain why I recieved an SMS text from Blockchain 3 minutes before the theft? If so, is it possible to locate the person who accessed my Gmail from that IP address?
To answer another question above. When I imported my paper wallet back to Blockchain, it was to my original wallet address that I'd used from the beginning.
