The best thing you can do is make a thread within the Account Help section and you will get help and advice on how to secure your System as well as your RuneScape account.
@C A Z: I don't think that their post is particularly off-topic, but I do think the cancer comment was a little uncalled for. A post on the first page
was
discussing carcinogenics so I won't hide the post, but I'll leave a note for the player. Thanks!
Community Manager for Jagex