Personally, I don't know if it could be a virus, but if it is a virus the person you are writing to should have written a reply thanking for your advice.
What I want to tell you is that I had big problems with s.one who was doing me every sort of things, and nobody believed me. At last, I studied so much on information security that I published a book. The publisher was the only one to believe me and he offered some help too. Now I am at least excluding some treats.
In other words, never count on others and try to solve the problem yourself. You, and only you, are the only person who knows everything and can decide if it is worrying or not. In this mad world, nobody will help you. I would do my best, but I have no elements. Regards.