analyzing-malware-sandbox-evasion-techniques

analyzing-malware-sandbox-evasion-techniques is a skill for Claude Code from mukul975/Anthropic-Cybersecurity-Skills. It costs 89 tokens per session (636 once invoked), scanned A, original, Apache-2.0.

A guide to finding signs that malware recognizes and avoids sandboxes or virtual machines. A sandbox is an isolated environment used to run suspicious code safely while recording its behavior.

In plain words
What is it for?
Use it to review Cuckoo Sandbox or AnyRun JSON reports for timing checks, virtual-machine artifacts, user-interaction checks, and environment fingerprints.
Why use it?
Malware may hide its actions when it detects analysis tools, virtual hardware, limited activity, or long delays. Recognizing these checks explains why a sandbox report shows little or no activity.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the cybersecurity-skills plugin — 56 skills shipped together

Good fit Use it to review Cuckoo Sandbox or AnyRun JSON reports for timing checks, virtual-machine artifacts, user-interaction checks, and environment fingerprints.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mukul975/anthropic-cybersecurity-skills/analyzing-malware-sandbox-evasion-techniques
About the project

Anthropic Cybersecurity Skills is a library of structured cybersecurity procedures for AI agents, covering security domains and mappings to established security frameworks. It is for authorized security analysis, penetration testing, incident response, research, defense, and education across compatible AI platforms. The catalogue entries package parts of this library as agent skills, instructions, or a plugin.

mukul975/Anthropic-Cybersecurity-Skills · 32,631 stars · on GitHub · mahipal.engineer

Install

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.

Any agent
npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill analyzing-malware-sandbox-evasion-techniques
Clone the repo
git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills

Made for: Claude Code.

Or install cybersecurity-skills, the plugin that ships this one along with the rest of its 56 skills.

Wrote 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.

agentmods badge for analyzing-malware-sandbox-evasion-techniques

README.md
[![agentmods](https://agentmods.dev/badge/skills/mukul975/anthropic-cybersecurity-skills/analyzing-malware-sandbox-evasion-techniques/github.svg)](https://agentmods.dev/skills/mukul975/anthropic-cybersecurity-skills/analyzing-malware-sandbox-evasion-techniques)
Your own site
<a href="https://agentmods.dev/skills/mukul975/anthropic-cybersecurity-skills/analyzing-malware-sandbox-evasion-techniques"><img src="https://agentmods.dev/badge/skills/mukul975/anthropic-cybersecurity-skills/analyzing-malware-sandbox-evasion-techniques/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for analyzing-malware-sandbox-evasion-techniques

Your own site · 80×15
<a href="https://agentmods.dev/skills/mukul975/anthropic-cybersecurity-skills/analyzing-malware-sandbox-evasion-techniques"><img src="https://agentmods.dev/badge/skills/mukul975/anthropic-cybersecurity-skills/analyzing-malware-sandbox-evasion-techniques.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 89 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 636 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Socket pass 7 Apr 2026
  • Snyk pass 7 Apr 2026
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high YARA Match · line 65
    YARA rule matched a known malware signature (reverse shell, backdoor, ransomware, C2 framework, or info stealer).
    Fix: Remove the malware payload or compromised file entirely. Investigate how it entered the skill and audit all other artifacts for additional indicators of compromise.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00089 $0.00636
Opus 5 $0.00044 $0.00318
Sonnet 5 $0.00018 $0.00127
Haiku 4.5 $0.00009 $0.00064

Measured 12d ago against content hash b64b9d5a5fb2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

analyzing-malware-sandbox-evasion-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 12d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/agent.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Origin

Copies of this mod

7 near-identical copies found in the catalogue:

skills/analyzing-malware-sandbox-evasion-techniques/SKILL.md · 72 lines

What it actually says

Analyzing Malware Sandbox Evasion Techniques

Overview

Sandbox evasion (MITRE ATT&CK T1497) allows malware to detect analysis environments and alter behavior to avoid detection. This skill analyzes behavioral reports from Cuckoo Sandbox and AnyRun for evasion indicators including timing-based checks (GetTickCount, QueryPerformanceCounter, sleep inflation), VM artifact detection (registry keys, MAC address prefixes, process names like vmtoolsd.exe), user interaction checks (mouse movement, keyboard input), and environment fingerprinting (disk size, CPU count, RAM). Detection rules flag samples exhibiting these behaviors for deeper manual analysis.

When to Use

  • When investigating security incidents that require analyzing malware sandbox evasion techniques
  • When building detection rules or threat hunting queries for this domain
  • When SOC analysts need structured procedures for this analysis type
  • When validating security monitoring coverage for related attack techniques

Prerequisites

  • Cuckoo Sandbox 2.0+ or AnyRun account for behavioral analysis reports
  • Python 3.8+ with json library for report parsing
  • Behavioral report exports in JSON format

Steps

  1. Parse Cuckoo/AnyRun behavioral report JSON files
  2. Extract API call sequences for timing-related functions
  3. Identify VM artifact detection via registry queries and WMI calls
  4. Detect sleep inflation by comparing requested vs actual sleep durations
  5. Flag user interaction checks (GetCursorPos, GetAsyncKeyState patterns)
  6. Score evasion sophistication based on technique count and diversity
  7. Map detected techniques to MITRE ATT&CK T1497 sub-techniques

Expected Output

JSON report listing detected evasion techniques with MITRE ATT&CK mapping, API call evidence, evasion sophistication score, and classification of evasion categories (timing, VM detection, user interaction, environment fingerprinting).

Files

What ships with it

3 files 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.

Changes

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.

  1. 12d ago First seen · 72 lines · 89 tokens per session scan A b64b9d5a5fb2

Subscribe to this mod's changes

analyzing-malware-sandbox-evasion-techniques is a skill published in the GitHub repository mukul975/Anthropic-Cybersecurity-Skills (32,631 stars, last pushed 12d ago), licensed Apache-2.0. It adds 89 tokens to every session and 636 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

analyzing-malware-sandbox-evasion-techniques

Detect sandbox evasion techniques in malware samples by analyzing timing checks, VM artifact queries, user interaction detection, and sleep inflation patterns from Cuckoo/AnyRun behavioral reports.

26zl/cybersec-toolkit · 46 tokens

analyzing-malware-sandbox-evasion-techniques

A malware-analysis procedure for finding signs that a malicious program is trying to detect or avoid a security sandbox. A sandbox is an isolated environment used to run suspicious files safely; Cuckoo Sandbox and AnyRun produce reports about what those files do.

killvxk/cybersecurity-skills-zh · 60 tokens

analyzing-malware-sandbox-evasion-techniques

Detect sandbox evasion techniques in malware samples by analyzing timing checks, VM artifact queries, user interaction detection, and sleep inflation patterns from Cuckoo/AnyRun behavioral reports.

plurigrid/asi · 46 tokens

analyzing-malware-sandbox-evasion-techniques

Detect sandbox evasion techniques in malware samples by analyzing timing checks, VM artifact queries, user interaction detection, and sleep inflation patterns from Cuckoo/AnyRun behavioral reports.

autohandai/community-skills · 46 tokens

analyzing-malware-sandbox-evasion-techniques

Detect sandbox evasion techniques in malware samples by analyzing timing checks, VM artifact queries, user interaction detection, and sleep inflation patterns from Cuckoo/AnyRun behavioral reports.

pinkpixel-dev/skills-collection-1 · 46 tokens

analyzing-malware-sandbox-evasion-techniques

Detect sandbox evasion techniques in malware samples by analyzing timing checks, VM artifact queries, user interaction detection, and sleep inflation patterns from Cuckoo/AnyRun behavioral reports.

marysatasselshaped667/skills-collection-1 · 46 tokens