If you're using Electrum or a derivative, you may receive a message like this:This message is, sent to you by a hacker. If you click the link in the message and install the software, then your BTC will be stolen. If you ignore the message, then you should be OK. Version 3.3.2 , released a week ago, makes the messages less readable/convincing, though you could still receive such messages.Note that altcoin derivatives of Electrum are very common, with over 1600 forks on github, and they will also be affected.More info:Discussion: