Created vondehi (markdown)

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Anonymous 2019-04-26 00:04:16 +00:00
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## vondehi
Vondehi is an in-memory unpacker for data compressed with `gzip` or `xz` (or
`xz` in LZMA1-mode). It basically performs these steps:
1. Set up a memfd using the `memfd_create` syscall. This file descriptor works
like a regular file, except the backing storage is RAM.
2. Fork, pipe the payload data to `zcat` or `xzcat`, which outputs everything
to teh memfd from step 1.
3. Run `execveat` on the memfd.
Of course, the code itself is hand-optimized x86 assembly, and is very crazy.