It probably is a virus. Try it it gets hidden once you uncheck "show hidden files" option. You can keep it that way or you can try a virus scan to see if it fixes the issue. you will otherwise have to format the memory after a backup.
may a trogen or corrupt file....by the way android don't have any affect on viruses because android based on linux kernel...but trogen can entered....once download es file exprorar and delete file from there then see
