I lost all my bitcoin about 18 months ago from the pop up within Electrum which asks you to download an update (Electrum 4). I was unaware of the existence of the scam at the time and I believe this was a well known scam which many users fell prey to.
I'm trying to see if "Reclaim Crypto" can do anything about it but I don't have much supporting evidence. The more victims of this scam who come forward the more likely it is that we may be able to gain some traction on recovering what we lost.
If you have fallen victim to this scam could you please report your experience to this link https://www.coinfirm.com/products/reclaim-crypto/
This is their email to me..

Coinfirm commented:

Dear Xxxx,

Thank you for this information.

In the absence of initial evidence, we may be able to determine your loss only at the later stage of the investigation.

Please note that our analysis and further investigation could take from a few months to couple of years.

Once we decide that we can assist in the recovery of the stolen cryptocurrency, we will propose an offer and agreement to the participants related to the accepted claims.

If you are aware of any other victims of the same case, please ask them to visit our website https://www.coinfirm.com/products/reclaim-crypto/ and submit their email. Reaching a larger group of victims increases the probability of recovering funds for the case. 

If you have any questions please contact us.

Team Reclaim Crypto

Thanks.. 

I just lost .73 of a bitcoin.. about £6k. I was making a small payment (about £50) through electrum and I got a message saying that I needed to apply a patch before the payment could be sent. The patch seemed to be legit and led directly to the electrum website. I downloaded Electrum 4.0. and when I started it up all my bitcoins had gone. my balance is now zero. What happened?