The values the debug version of CRT memory manager fills memory with.
dbgheap.c:
static unsigned char _bNoMansLandFill = 0xFD;Â Â /* fill no-man’s land with this */
static unsigned char _bDeadLandFill  = 0xDD;  /* fill free objects with this */
static unsigned char _bCleanLandFill = 0xCD;  /* fill new objects with this */
static unsigned char _bAlignLandFill = 0xBD;  /* fill no-man’s land for
aligned routines */
Additionally, debug compilation (optimization turned off?) produces code which uses 0xCC fill to initialize variables on stack and