If he didn't put the link in his reply himself and his antivirus program didn't either, it was some program on his PC indeed. Nothing indicates that it's your PC.
Deleting the mail, after reading the answer, is a good idea.
But, since you ask, it would be nice if you posted the link in your reply. Leave off the http:// or https:// and replace all dots with the text (dot). The start of the link showing this thread would become www(dot)cnet(dot)com/forums/ that way. Then nobody can click on it, and - whatever it is - it's harmless.
I am unsure where to enter this question so I hope that if this is not in the correct location, it will be directed to the correct one!
I sent a question to a friend and his reply contained two identical answers.
The first had an unknown link after his greeting to me and the second was exactly the same but without the link.
I could copy and past the link here, but until/unless I am so invited, I think that I had better not!
I phoned him to inform him and he is going to do a scan of his computer with his antivirus/malware scanner.
I am minded to delete the reply but would wait to see if any technical person wishes to see the link to analyse if it is malware or not to report it to the appropriate authorities.
Thanks for any advice in advance.