Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/justinedevs/premortem/anti-debugging-techniquesnpx skills add JustineDevs/premortem --skill anti-debugging-techniquesgit clone --depth 1 https://github.com/JustineDevs/premortemWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/justinedevs/premortem/anti-debugging-techniques)<a href="https://agentmods.dev/skills/justinedevs/premortem/anti-debugging-techniques"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/anti-debugging-techniques.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00046 | $0.03845 |
| Opus 5 | $0.00023 | $0.01922 |
| Sonnet 5 | $0.00009 | $0.00769 |
| Haiku 4.5 | $0.00005 | $0.00384 |
Grade A, and why
anti-debugging-techniques scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
100% identical to anti-debugging-techniques — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 408 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SKILL: Anti-Debugging Techniques — Detection & Bypass Playbook
AI LOAD INSTRUCTION: Expert anti-debug techniques across Linux and Windows. Covers ptrace, PEB flags, NtQueryInformationProcess, timing attacks, signal-based detection, TLS callbacks, VEH tricks, and all corresponding bypass methods. Base models often miss the distinction between user-mode and kernel-mode detection and the correct patching strategy for each.
0. RELATED ROUTING
- code-obfuscation-deobfuscation when the binary also uses control flow flattening, VM protection, or string encryption
- vm-and-bytecode-reverse when the anti-debug sits inside a custom VM dispatcher
- symbolic-execution-tools when you want to symbolically skip anti-debug checks entirely
Advanced Reference
Also load ANTI_DEBUG_MATRIX.md when you need:
- Complete cross-reference matrix of technique × OS × detection method × bypass method
- Per-technique reliability ratings and false-positive notes
- Tool compatibility chart (GDB, x64dbg, WinDbg, Frida, ScyllaHide)
Quick bypass picks
| Detection Class | First Bypass | Backup |
|---|---|---|
| ptrace-based (Linux) | LD_PRELOAD hook ptrace() → return 0 |
Kernel module to hide tracer |
| PEB.BeingDebugged (Windows) | Patch PEB byte at fs:[0x30]+0x2 |
ScyllaHide auto-patch |
| Timing check (rdtsc) | Conditional BP after rdtsc, fix registers | Frida hook rdtsc return |
| IsDebuggerPresent | NOP the call / hook return 0 | x64dbg built-in hide |
| INT 2D / UD2 exception | Set VEH to handle gracefully | TitanHide driver |
1. LINUX ANTI-DEBUG TECHNIQUES
1.1 ptrace(PTRACE_TRACEME)
The classic self-attach: a process calls ptrace(PTRACE_TRACEME, 0, 0, 0). If a debugger is already attached, the call fails (returns -1).
if (ptrace(PTRACE_TRACEME, 0, 0, 0) == -1) {
exit(1); // debugger detected
}
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 5d ago First seen · 408 lines · 46 tokens per session scan A 4f26ae837d36
anti-debugging-techniques is a skill published in the GitHub repository JustineDevs/premortem (2 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 46 tokens to every session and 3,845 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to anti-debugging-techniques, differing in 0 lines, and is treated as a copy.
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