POSTDump

Another tool to perform minidump of LSASS process using few technics to avoid detection.

POSTDump is the C# / .NET implementation of the ReactOS minidump function (like nanodump), thus avoiding call to the Windows API MiniDumpWriteDump function. The dump logic code is saved under the POSTMinidump project, feel free to use it for your own projects.

Such as NanoDump, you can encrypt or use an invalid signature for the minidump.

Usage of ProcExp driver is supported to dump/kill protected processes.

Usage

Dump LSASS:

c:\Temp>PostDump.exe --help

"[PPL DISABLED]\n" +
"--snap - Use snapshot technic\n" +
"--fork - Use fork technic [default]\n" +
"--duplicate-elevate - Look for existing lsass handle to duplicate and elevate\n" +
"--elevate-handle - Open a handle with low privileges and duplicate it to gain higher privileges (default: true)\n" +
"--asr - Attempt dump using ASR bypass (no signature/encrypt available, .dmp file written on disk)\n" +

"[PPL ENABLED]\n" +
"--duplicate-elevate - Look for existing lsass handle to duplicate and elevate\n" +
"--werfaultsecure - Attempt dump using vulnerable werfaultsecure to dump PPL process\n" +
"--driver, -d - Use Process Explorer driver to open lsass handle and dump lsass\n" +
"--kill, -k [processID] - Use Process Explorer driver to kill process and exit\n" +

"[GLOBAL]\n" +
"--help, -h - Display help\n" +
"--encrypt, -e - Encrypt dump in-memory\n" +
"--signature, -s - Generate invalid Minidump signature\n" +
"--live - Parse creds from memory without writing into file on disk\n" +
"--parse-dump - Parse creds from dump file\n" +
"--outfile, -o - Output file where to write dump\n" +

Evasion

• Usage of indirect syscall along with halo's gate technic to retrieve syscalls IDs
• No memory Allocation/Protection call is performed for indirect syscall, instead, free RWX codecave found in the current process are used
• ETW patching
• No call to MiniDumpWriteDump
• Live lsass creds parsing (no dump writing)

Improvements idea

• Implement more dump technics (seclogon, PPLMedic, Shtinkering ..)
• More evasion technics (callstack spoofing)
• Implement Godfault to avoid driver usage

Compilation

• You can build using .NET Framework 4.5.1 as-is.
• Depending of the CLR version installed on the system where you execute PostDump, you may need to downgrade to .NET 3.5 more info here

Sponsors

I work at POST Luxembourg and thank them for allocating some time for me to develop and maintain this project! Visit POST website at https://www.post.lu/business/produits-et-services/cyberforce.

Credits

• s4ntiago_p for the awesome NanoDump tool
• Yaxser (procexp driver)
• SECFORCE for finding RWX codecave
• 0xAbdullah for ASR technic
• cube0x0 for Minidump lib to parse lsass

Disclaimer

This software has been created purely for the purposes of academic research and for the development of effective defensive techniques, and is not intended to be used to attack systems except where explicitly authorized. Project maintainers are not responsible or liable for misuse of the software. Use responsibly.