scdbg fopen mode Author: David Zimmer Date: 03.08.11 - 4:58pm
Added a new option to scdbg the other day that allows it to work with file format shellcode that scans for open file handles using GetFileSize().
When ReadFile is called the -fopen mode allows the shellcode to actually access data within the target file. If you add the -i interactive mode as well, then the retrieved (and probably decoded) buffers are then written to disk as a randomly named tmp file when a write api is called.
All in all pretty painless capture of decoded and dropped executables!
$ ./sctest -f test.sc -fopen bad.pdf -s -1 -i
fopen(bad.pdf) = 4d565c
Loaded 312 bytes from file test.sc
Initilization Complete..
Interactive Hooks enabled
Max Steps: -1
Using base offset: 0x401000
401083 GetFileSize(4) = 2031b
401112 GlobalAlloc(sz=2031b) = 60000
401118 SetFilePointer(hFile=4, dist=0, FILE_BEGIN)
401132 ReadFile(hFile=4, buf=60000, numBytes=2031b)
401147 CreateFile(x.exe)
Interactive mode local file: /tmp/WHhUmhtM
401158 WriteFile()
401176 WinExec(x.exe)
Couple other updates include:
exe - added hooks for SetFilePointer, ReadFile, strstr,
strtoul, FreeLibrary, GlobalFree, GetCurrentProcess,
TerminateProcess
/bp and /laa now accept api names to break at
dll - enabled support for TEST A8 and A9 (seems ok but need more testing..)
updated binaries and source uploaded.
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