My gmail has been sending messages to people in my contact history. I say contact history instead of actual contacts because I never designated anyone as a contact, it just seemed to pick random people whom I have emailed in the past (one of them was even an address I used to unsubscribe from a mailing list). The first message had the subject "Hellofriend" or something close to that. The second message, which was sent about 14 hours later said "HelloBoss." Each message has nothing in it except a link which I dare not open. Both were sent to the same list of people. I have sent a warning email telling them not to open these, but if the messages keep being sent, they'll have no choice but to block me, which I don't want. I can't help thinking that it had something to do with a message I received which looked odd, but didn't go into my spam folder, so I opened it in curiosity. The weird part is that despite these messages being apparently sent from my address, they don't show up in my Sent folder. The only reason I knew about them was because my dad was one of the targets and he asked me about it.
What can I do about this? I thought it was only going to happen once and my warning message was a good enough precaution, but after the second message was automatically sent, I'm thinking that they will continue and I want to stop that from happening. To be honest, I'm not even sure this is a virus. And since gmail is web-based email, I know it can't be the computer. Would it be appropriate to contact Google?