Really? Those scripts are still in "kiddie" level? Amazing

So that virus can be acquired usually through entering untrusted sites, now I know! and I feel relieved because I'm not that kind of person who easily enter to those such kind of sites. I'm not too dumb to believe in " earn free bitcoins, click here" statements. 

I think from now on I will double check the address carefully every time I will send coins to someone because honestly, I always skip checking the address of my receivers before, I only look at the last letter/number and if it matches from what I copied then that's it.

thank you for giving us this news i will send this to all my friend to know this virus hope this will no longer exist. i so scared with this virus because are account will be ban if they detect a copy paste in some post.

lol i think the virus that op is talking about is only copying and pasting bitcoin addreses and not totally everything that you do . i guess it was a malware that primary objective  is to steal coins from other users in the form of copy and pasting different bitcoin addreses. the only way to avoid it is to be aware and always double check after you copy and pasted your bitcoin address. another tip is make sure you only download files that is from a known or trusted source and always scan the files before installing to check whether it is infected by the virus or not.

I think is not reallizable, because your edited btc adres must owned by malware author, if malware change only few characters your money going to nowhere