Previous versions often left unpacked code in clear memory. Update 021 likely uses sparse unpacking – only decrypting small code chunks immediately before execution and re-encrypting them afterward. This frustrates memory dumping tools.
Using file:
obfuscate_021_upd.bin: ELF 64-bit LSB executable, x86-64, dynamically linked, stripped
Running strings reveals nothing obvious – no plaintext flag, no /bin/sh, just libc references.
Running the binary:
$ ./obfuscate_021_upd.bin
Enter key:
Entering random data → "Wrong" exit.
Instead of just renaming variables, "obfuscate 021 upd" pushes entire functions into a custom virtual machine (VM). The original x86/ARM instructions are replaced with bytecode for a fictitious CPU. The update adds a new instruction set (say, 021-specific opcodes) that previous VM breakers do not recognize.
Recent updates to IDA Pro (version 9.0+) include heuristics against flattened control flow. You can also use the Hex-Rays microcode API to simplify opaque predicates by constant propagation. Look for community scripts – often, within weeks of an "021 UPD" release, deobfuscators appear on GitHub. obfuscate 021 upd
Unfortunately, sophisticated obfuscation is used by malware authors. An "021 update" in a banking trojan or ransomware could mean the malware has evolved to evade next-gen antivirus engines that rely on behavioral analysis. Security vendors must reverse these updates to create signatures.
Break at strcmp or memcmp after input read.
Using gdb:
gdb ./obfuscate_021_upd.bin
break strcmp
run
Enter key: AAAAAAAAA
Observe strcmp called with:
So the correct key is d0nT_0bFuSc4t3_m3!.
Use tools like Detect It Easy (DIE) or PEiD (on Windows) or file command on Linux. Many obfuscators leave unique section names (e.g., .obfx021, .upd21). Look for high entropy in the .text section. Previous versions often left unpacked code in clear memory
If you want, I can convert this into a checklist for your CI (e.g., GitHub Actions or GitLab CI) or tailor the report to a specific language/platform—specify which one.