Virus - When your just not sure!!!

A

AC Question

I'll try to explain as best I can. I received a message from a known contact. It went to one of his groups.
of which I am a member. I suspect it originated from his dropbox account. Soon after I received two
messages from numbers I did not recognize. Both had multimedia messages included and I clicked download
on the first before I took time to think on my actions. The first message said, "Thank you. Operation is in progress."
(That message could dovetail with the original because it was one of those 'forward to fourteen people in the next ten minutes, etc'
I did not download the second. I have an HTC Evo Design 4g. My cell has been running slow due to a candy crush addicition,
but it seemed to slow even more after. (might just be my paranoia). The next day I received a another text message from
a known contact. This one said, From: Anonymous Subject: (none) Message size 1KB Expires: Aug 25 and again a download
button which I did not press. When tapping on the message I do not get a message options menu. To delete for example.
I did move candy crush to my SD card and all seems much faster and back to normal in that regard but the errant messages
concern me. Thoughts?