Can Mossad kill me in US?

So after reading about Israel crimes, I went to an Israel chatroom to denounce Israeli crimes against humanity, and I made a fabricated threat against Israel. Then I was contacted by someone who pretended to be a christian, and then my antivirus detected a win trojan. After that, the person tried to tempt me to tell him where I live. At that moment, I left the site. Later on, I found out that the site was created in Israel! The guy also tried to scare me by telling me about Mossad inations in Egypt, etc. I think that the Mossad are after me because they deem me a threat. Could they kill me in US, even if I am an American voicing my opinion?