Deepsea Obfuscator V4 Unpack
DeepSea v4 encrypts the .resources section. To unpack resources:
| Problem | Likely Cause | Solution |
| :--- | :--- | :--- |
| "BadImageFormatException" after dump | Missing or corrupted metadata directory | Rebuild with dotnet peverify and manual patching. |
| Strings still encrypted after decryption | Nested decryption layers (shell inside shell) | Run the dumping process twice (recursive unpacking). |
| Application crashes on startup after unpack | Anti-tampering checksum verification | NOP the Assembly.Load validation method using dnSpy patch. |
| Methods show // Token: 0x06000123 | DeepSea erased symbolic names | Manual renaming or static analysis of cross-references. | deepsea obfuscator v4 unpack
DeepSea, like many packers, uses pushad at the start to save the register state and popad right before jumping to the OEP to restore it. DeepSea v4 encrypts the
Most DeepSea v4 samples are packaged as a native executable (C/C++ launcher) that writes the .NET assembly into memory. Alternatively: If the file runs as a pure
Alternatively: If the file runs as a pure .NET assembly (managed entrypoint), launch dnSpy, attach to the process immediately after startup, and pause execution.
Unlike traditional jump obfuscation, DeepSea v4 replaces br and call instructions with a custom VM. The original IL code is translated into a bytecode that only the embedded DeepSea interpreter understands. A typical if/else block becomes a massive switch dispatcher inside the VM.
Trying to unpack DeepSea v4 with only dnSpy will lead to an infinite loop of crashes. You need the right tools: