File in trash called ÿøÿá./ex.if␀

Someone used my iMac and after use I found the file name above in my Trash. I can not dump it even if I shutdown and restart my iMac. I can choose Empty trash and it sounds like it is emptying the trash but this file? still stays. Anyone seen this and know what to do?
Thanks.

This is why it's ALWAYS a bad idea to let someone use your personal account on a Mac, and why Macs have guest accounts. Hopefully, lesson learned there.

I would suggest resetting Safari or whatever web browser they may have used. Backup your bookmarks first.

Thanks chas_m, that worked. I will follow your advice about guest accounts in the future. Appreciate your help!