If its keyloger , firewall cant help about it , becuse actually keyloger is not a virus , ppl use it just to protect thier password , i mean if you forget your password , you can get it back by the keyloger , which show you all your password you use'd.
But if its was a trojan ( Virus ) , i have no idea how he scammed him , and btw , he need antivirus to find virus , not a firewall which help only against hackers ( computer hackers , not game :\ )
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