game

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打开程序显示一些符号,让你玩游戏,赢了就有flag

用OD打开,搜素字符串,找到flag的定位

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运行到这里,运行这个函数,就可以得到flag

IDA

放进IDA,找到main函数

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进入sub_457AB4()

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写个脚本运行

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arr1 = [18, 64, 98, 5, 2, 4, 6, 3, 6, 48, 49, 65, 32, 12, 48, 65, 31, 78, 62, 32, 49, 32,
1, 57, 96, 3, 21, 9, 4, 62, 3, 5, 4, 1, 2, 3, 44, 65, 78, 32, 16, 97, 54, 16, 44,
52, 32, 64, 89, 45, 32, 65, 15, 34, 18, 16, 0]
arr2 = [123, 32, 18, 98, 119, 108, 65, 41, 124, 80, 125, 38, 124, 111, 74, 49,
83, 108, 94, 108, 84, 6, 96, 83, 44, 121, 104, 110, 32, 95, 117, 101, 99,
123, 127, 119, 96, 48, 107, 71, 92, 29, 81, 107, 90, 85, 64, 12, 43, 76, 86,
13, 114, 1, 117, 126, 0]
str=''
for i in range(0,56):
arr2[i] ^= arr1[i]
arr2[i] ^= 0x13
str =str + chr(arr2[i]);

print(str)

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Hello,CTF

一个exe,运行结果如下:

1567821831010

IDA找到main函数

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a键直接的到flag