Ok, maybe I have to explain what just happened with me -

I used electrum-2.9.3 to send some small amount 0.015 to 149xne93ppwQLww733hNnGmFqj51rNPjBC

I've checked all (sum, fee etc) all was correct but money were sent also to 144BdLLSifbZJEmqnHy8i1QkRdrxxHeFf3

see https://btc.com/ebdd24ff41f92aeef948133e788487e4ce1019eae85949c6be6455e27fbb38cf

I downloaded Electrum from OFFICIAL SITE https://www.electrumsource.org/#download for Windows Standalone.

And used cold storage for my wallet.

I'm shocked.

Thes same just happened with me !!!! Don't use Electrum for a while.
My money were stolen to this address: https://blockchain.info/address/144BdLLSifbZJEmqnHy8i1QkRdrxxHeFf3