инструмент ollydbg 1.10
код для демо
ebp-44:\>dir /b
ebp-44.cpp
ebp-44:\>type ebp-44.cpp
#include <stdio.h>
#include <windows.h>
int main (void)
{
char *mystrarray[] = {
"humble bee", "bumblebee", NULL,"my naughty string", "my notty string",
"my nauty string","my native string",NULL, "want to string me ",
"come on string with me","string sings the song strong", NULL, NULL,
"what's this string doing here in onederlaand", NULL,NULL,NULL,NULL,
"teaching lice to string the strong","my golden bug is strumming here",
"my gold trinket's stringing here", "my gold trinket's stringing hare",
"want to string me ","come string me", "string sings the song strong",
NULL,NULL,NULL,NULL,NULL,"my gold trinket's stringing hire",NULL,NULL
};
for (int i = 0; i < _countof(mystrarray) ; i++ )
{
register char *yoyo;
yoyo = mystrarray[i];
printf("%s\n", yoyo);
}
return 0;
}
ebp-44:\>cl /nologo /Zi /analyze /W4 ebp-44.cpp /link /RELEASE
ebp-44.cpp
ebp-44:\>ebp-44.exe
humble bee
bumblebee
(null)
my naughty string
my notty string
my nauty string
my native string
(null)
want to string me
come on string with me
string sings the song strong
(null)
(null)
what's this string doing here in onederlaand
(null)
(null)
(null)
(null)
teaching lice to string the strong
my golden bug is strumming here
my gold trinket's stringing here
my gold trinket's stringing hare
want to string me
come string me
string sings the song strong
(null)
(null)
(null)
(null)
(null)
my gold trinket's stringing hire
(null)
(null)
ebp-44:\>OLLYDBG.EXE ebp-44.exe
ebp-44:\>
установите breakpoint on main and f9
для запуска исполняемого файла, когда он сломается при основном хите ctrl+t (condition to pause run trace)
check mark condition is true
флажок в поле условия введите
STRING [[ EBP-90]] == "my gold trinket's stringing hare"
{EBP-90] взято из просмотра разборки, может отличаться в вашем случае используйте соответствующий адрес
0040111A |MOV ECX, DWORD PTR SS:[EBP-8C] ; yoyo = mystrarray[i];
00401120 |MOV EDX, DWORD PTR SS:[EBP+ECX*4-88]
00401127 |MOV DWORD PTR SS:[EBP-90], EDX
0040112D |MOV EAX, DWORD PTR SS:[EBP-90] ; printf("%s\n", yoyo);
00401133 |PUSH EAX
00401134 |PUSH ebp-44.0041235C
00401139 |CALL ebp-44.printf
нажмите ctrl+f11 (обвести)
ollydbg сломается, если [ebp-90] будет содержать строку
Log data, item 0
Message=Conditional pause: STRING [[ EBP-90]] == "my gold trinket's stringing hare"
см. сборку выше, edx передает нашу строку в [ebp-90]
EDX=004122D0 (ebp-44.004122D0), ASCII "my gold trinket's stringing hare"
Stack SS:[0013FEE8]=004122D0 (ebp-44.004122D0), ASCII "my gold trinket's stringing hare"
ebp-44.cpp:18. yoyo = mystrarray[i];
вот отпечаток ebp при поломке
Log data, item 0
Message=ebp = 13ff78 ebp-90 = 13fee8 [ebp-90] = 4122d0 [[ebp-90]] = 6720796d STRING [[ebp-90]] = my gold trinket's stringing hare " see 6d792067 ascii equivalent for "my g"
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schedule
12.05.2014