The Cagliari family of viruses are very dangerous memory resident parasitic viruses. They hook INT 21h and write themselves to the end of .COM files that are executed. On May the 1st they erase the FAT sectors on disks A, B, C, D and then display the message: caGLiArI The similar string is used by virus in its 'Are you here?' call - while installing the virus calls INT 21h with AX=FFABh, the memory resident copy returns 'CA', ' GL', 'IA', 'RI' in registers AX,BX,CX,DX. Research Cagliari