Every time I open Windows Live Messenger, it asks if I want to open this swf file?

When I open my WLM window, it asks if I want to save a file called "234x60_1f.swf". Sometimes it's 234x60_3f.swf.....What is this? Do I have a virus? it says it's from crtv.mate1.com (I haven't visited this link, so I don't know if it's malicious or not). and if someone sends me a message it repeatedly asks me to open that file. Also, it randomly goes to appear offline. Please help.