Itel 1.3mp Of Fore And Back Camera

Dear friends, i have memorycard of storage capacity about 8GBs. but it is affected by invisible virus. now it is storing and allow play of items of 242 megabytes only and other items tobe added on memory immediately folders of memory card disappear from phone until i stop to try to add other files. its abig problem for me becouse i have formated it and re_add items again but the stuation remains the same. so i need your crucial_support?????