This blog post introduces PADDQ instruction from intel SIMD – SSE2 extension and how it can be used to encode and decode a shellcode. Developed encoder creates polymorphic shellcode – however the decoder assembly stub remains static. PADDQ instruction PADDQ instruction simply adds 2 packed qwords in the first operand to corresponding 2 packed qwords in the second operand. First …
Tag: python
Encoding with MMX-PUNPCKLBW instruction
In this blog post I will describe how to encode/decode arbitrary byte sequence with PUNPCKLBW instruction from MMX instruction set. PUNPCKLBW instruction Arcane denotation PUNPCKLBW stands for Pack/Unpack/Lower/Byte/Word. This instruction is used to combine two data elements into one. See following picture PUNPCKLBW unpacks and interleaves the low-order data elements of the destination operand and source operand into the destination …
Replicating orderbooks from Websocket stream with Python and Asyncio
Introduction We are currently working on time-series database solution for collecting high-frequency crypto-exchanges data – namely for tick data and one-minute orderbook snapshots. We’ve developed REST API collector bots which are continuously fetching data from numerous REST API endpoints and saving them to database. This solution would work in the perfect world but that’s not where we do live. During …