I have one theory, but will not say it, because I am now the only one with this problem. So maybe later...
But I am 100% sure I have visited electrum.org in time of download, but did not check file signature after.
My funds are gone and we probably are unable to investigate, what exactly, or better how exactly this happened, that is all.
Thanks to all for your time and help.

You think, that my smartphone is not clean too?
I have tried another ISP too (on my cell phone), but still when I visit eleclrum .org, it will redirect me to electrum.org
If you say, that you have no redirection, it is weird...
But let think about it - you are a hacker trying to steal some BTCs, you will have webpage with the similar address, will you redirect this webpage to the legal webpage or you will try to force people to download malicious wallet from your webpage?
Or have this two domains the same owner? I do not think so.

https://www.whois.com/whois/eleclrum.org

https://www.whois.com/whois/electrum.org

I know,it is only my fault...
Maybe "original" site was hacked in time of my download.
But the redirection from "hackers" site eleclrum to original electrum site is still realy weird. It will redirect me like that on all my PCs, smartphone etc.

Yes, the fake one comes from e l e c l r u m .org not from electrum.org.
But when I type: e l e c l r u m .org (without spaces of course) it will redirect me to electrum.org, when I can download clean wallet right now.
Maybe I had some malware and now I am clean, but the redirection is weird...

Yes, I know I installed malicious version of electrum, but I still do not understand, how can I download different file from Firefox and different from MS Edge? When I visit electrum.org from Firefox, it looks same as on Edge, it has the same SSL certificate.
My only extension on Firefox is Adblocker.
I know, it is my fault, that I did not check the signature. I am only affraid, if I still have some malware on PC, but that is another problem.
But right now I have downloaded "clean" wallet from Firefox too, it is weird...
Once again, thank you for your help.

You are probably right. I did not do signature check (I am stupid, I know).
I write this on latest Firefox, I also downloaded Electrum from Firefox. Now, when I downloaded it from MS Edge, it is a little bit smaller file, so I probably had something wrong with Firefox...

Hello,
sorry for my poor english. I have lost all my BTCs just after open Eletrum v.3.3.3
I will try to describe what happened.
I had on my PC with Win 10 an old version of Electrum - v. 2.5.2. So I opened it, but its status was still "Synchronizing"
So I thought I probably had an old version and I looked on webpage Electrum.org for a new one and downloaded this file: https[Suspicious link removed]
When it started, it was synchronized maybe after 30 seconds and I saw all my funds, but after a while new outgoing transaction have appeared,which sent all my BTCs to this address:  1NRzWJZHJbUbKTjYtS1xKmFF1uZq7p6rXD   
Transaction ID is:  48d5071da6d8859f69764ca951186de63b719f6067350f3abc7bc4f9566f4f35
But I realy did not make any transaction, it was made somehow automaticaly.
My first idea was - I have malware on my PC, but I have installed Comodo internet security with active realtime protection on my PC, which did not found any malware and I checked it with Eset online scanner with the same result.
Can someone explain to me, what could happened? There is no chance to get my BTCs back, am I right?
Thank you.