Thanks so much!!
For future reference, if a recovery phrase is compromised, what should be done?
What if there are still funds in the old account? Thanks again
If just the mnemonic is compromised, you should transfer your coins to a new
blockchain.info account, which has a different mnemonic.
But if your computer is compromised, you should transfer those coins to a paper
wallet that is generate offline from a different computer. After that is successful,
you could choose, at your leisure, to move the coins to a more secure device, such
as a hardware wallet or a new/clean computer software wallet.
In emergencies, you should pay a higher fee to move your coins, so that an attacker
who has your compromised keys does not beat you to a block, by double spending
with a higher fee.
Online wallets should only be used for small amounts of bitcoin, while large amounts
should be maintained in cold storage systems if possible.
Never keep large amount of bitcoins on exchanges unless you are currently trading
or willing to lose them to hacking. Exchanges and malicious software on computers
are the two likely reasons why you will lose control over your bitcoins.
Before sending your bitcoins in any transaction, always check the mempool and see
what the current levels are at, so that you are aware of the current situation. Not
checking before you send your tx is like not looking both ways before crossing the
street.
If you follow the above, you should be ahead of the average bitcoiner.