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Scans Markdown (.md) files for malicious code injection including XSS, prompt injection, script injection, obfuscated payloads, and supply chain attack vectors. Use when auditing .md files for security threats or when the user mentions scanning markdown for malicious content.
| name | markdown-injection-scanner |
| type | workflow |
| description | Scans Markdown (.md) files for malicious code injection including XSS, prompt injection, script injection, obfuscated payloads, and supply chain attack vectors. Use when auditing .md files for security threats or when the user mentions scanning markdown for malicious content. |
| context | fork |
| agent | security-engineer |
| when_to_use | When scanning .md files for injection attacks, prompt injection, embedded malware, or when auditing documentation files for security threats |
| allowed-tools | Read, Glob, Grep, Bash |
| argument-hint | [target directory path] |
| user-invocable | true |
| effort | 3 |
Scans all .md files in a target directory for 18 categories of malicious code injection.
Uses regex pattern matching across the entire file corpus with parallel subagent execution for speed.
/markdown-injection-scanner [target-directory]
If no directory is specified, ask the user to provide one.
Count all .md files in target directory (recursive).
Sample 2-3 files to understand the file structure and content type (design docs, documentation, config, etc.).
Report file count and content type before proceeding.
Execute scans in 3 parallel batches using subagents for speed. Each subagent uses search_files with the target directory path and *.md file pattern.
| # | Category | Regex Pattern | Threat |
|---|---|---|---|
| 1 | Script tags | <script[^>]*> | Embedded JavaScript execution |
| 2 | HTML Event Handlers | (onclick|onerror|onload|onmouseover|onfocus|onblur|onresize|onsubmit|onchange|oninput|onkeydown|onkeyup|onkeypress|ontouchstart|onmouseenter|onmouseleave)\s*= | Inline JS via HTML attributes |
| 3 | JS/VBScript Protocol | (javascript:|vbscript:) | Malicious link protocols |
| 4 | Dynamic Code Execution | (eval\s*\(|Function\s*\(|setTimeout\s*\(|setInterval\s*\() | Code execution via eval/setTimeout |
| 5 | DOM Manipulation | (document\.(cookie|domain|write)|window\.(location|open)|XMLHttpRequest|fetch\s*\() | DOM-based attacks |
| # | Category | Regex Pattern | Threat |
|---|---|---|---|
| 6 | Base64 Payloads | (base64|atob|btoa|b64decode|b64encode)[\s(] | Encoded malicious content |
| 7 | Data URI Injection | data:\s*(text/html|application/javascript|text/javascript) | Inline HTML/JS via data URIs |
| 8 | SVG Injection | <svg[^>]*> | SVG-based XSS vectors |
| 9 | Hex/Unicode Encoding | (\\x[0-9a-fA-F]{2}|\\u[0-9a-fA-F]{4}|&#x[0-9a-fA-F]+;) | Obfuscated character encoding |
| 10 | Hidden Text — display:none | <(span|div|p)[^>]*style\s*=\s*['"][^'"]*display\s*:\s*none | Hidden content tricks |
| 11 | Hidden Text — font-size:0 | font-size\s*:\s*0 | Invisible text |
| # | Category | Regex Pattern | Threat |
|---|---|---|---|
| 12 | HTML Tag Injection | <(iframe|embed|object|link|meta|form|input|textarea|button)[\s>] | Injected HTML elements |
| 13 | Suspicious Markdown Links | \[.*?\]\(data: then \[.*?\]\(javascript: then \[.*?\]\(vbscript: | Malicious link targets |
| 14 | Prompt Injection (NL) | (?i)(ignore\s+(all\s+)?previous\s+instructions|you\s+are\s+now|forget\s+(all\s+)?previous|system\s*:\s*you\s+are|disregard\s+(all\s+)?prior|override\s+(all\s+)?instructions|new\s+instructions?:|IMPORTANT:.*ignore|do\s+not\s+follow) | AI/LLM prompt hijacking |
| 15 | Prompt Injection (Token) | (?i)(\[INST\]|\[\/INST\]|<|im_start|>|<|im_end|>|<|system|>|<|user|>|<|assistant|>|Human:|Assistant:|###\s*System\s*Prompt|BEGIN\s+HIDDEN|END\s+HIDDEN) | LLM token format injection |
| 16 | Shell Command Injection | (curl\s+|wget\s+|bash\s+-c|sh\s+-c|powershell|cmd\.exe|/bin/sh|/bin/bash|rm\s+-rf|chmod\s+777|sudo\s+) | Shell command execution |
| 17 | Executable File Links | (https?://[^\s)>\]]*\.(exe|bat|cmd|ps1|sh|msi|dll|vbs|wsf|hta|scr)) | Links to malicious executables |
| 18 | Malware Keywords | (?i)(steganograph|obfusc|malware|payload|exploit|backdoor|trojan|keylog|ransom|phish) | Direct malware references |
Use 3 subagents via use_subagents, each with prompts corresponding to their batch patterns above. Replace [TARGET_DIR] with the actual target directory.
Subagent 1 — Script and Code Injection:
Search for script and code injection patterns in .md files in "[TARGET_DIR]". Use search_files with these regex patterns on *.md files, one at a time:
1. `<script[^>]*>`
2. `(onclick|onerror|onload|onmouseover|onfocus|onblur|onresize|onsubmit|onchange|oninput|onkeydown|onkeyup|onkeypress|ontouchstart|onmouseenter|onmouseleave)\s*=`
3. `(javascript:|vbscript:)`
4. `(eval\s*\(|Function\s*\(|setTimeout\s*\(|setInterval\s*\()`
5. `(document\.(cookie|domain|write)|window\.(location|open)|XMLHttpRequest|fetch\s*\()`
Report all findings per pattern.
Subagent 2 — Obfuscation and Encoding:
Search for obfuscation and encoding patterns in .md files in "[TARGET_DIR]". Use search_files with these regex patterns on *.md files, one at a time:
1. `(base64|atob|btoa|b64decode|b64encode)[\s(]`
2. `data:\s*(text/html|application/javascript|text/javascript)`
3. `<svg[^>]*>`
4. `(\\x[0-9a-fA-F]{2}|\\u[0-9a-fA-F]{4}|&#x[0-9a-fA-F]+;)`
5. `<(span|div|p)[^>]*style\s*=\s*['"][^'"]*display\s*:\s*none`
6. `font-size\s*:\s*0`
Report all findings per pattern.
Subagent 3 — Injection Vectors:
Search for injection vectors in .md files in "[TARGET_DIR]". Use search_files with these regex patterns on *.md files, one at a time:
1. `<(iframe|embed|object|link|meta|form|input|textarea|button)[\s>]`
2. `\[.*?\]\(data:` then `\[.*?\]\(javascript:` then `\[.*?\]\(vbscript:`
3. `(?i)(ignore\s+(all\s+)?previous\s+instructions|you\s+are\s+now|forget\s+(all\s+)?previous|system\s*:\s*you\s+are|disregard\s+(all\s+)?prior|override\s+(all\s+)?instructions|new\s+instructions?:|IMPORTANT:.*ignore|do\s+not\s+follow)`
4. `(?i)(\[INST\]|\[\/INST\]|<\|im_start\|>|<\|im_end\|>|<\|system\|>|<\|user\|>|<\|assistant\|>|Human:|Assistant:|###\s*System\s*Prompt|BEGIN\s+HIDDEN|END\s+HIDDEN)`
5. `(curl\s+|wget\s+|bash\s+-c|sh\s+-c|powershell|cmd\.exe|/bin/sh|/bin/bash|rm\s+-rf|chmod\s+777|sudo\s+)`
6. `(https?://[^\s)>\]]*\.(exe|bat|cmd|ps1|sh|msi|dll|vbs|wsf|hta|scr))`
7. `(?i)(steganograph|obfusc|malware|payload|exploit|backdoor|trojan|keylog|ransom|phish)`
Report all findings per pattern.
If any patterns matched in Phase 2, read the flagged files to:
If zero patterns matched, skip to Phase 4.
# Markdown Injection Scan Report — [TARGET_DIR]
## Summary
- **Files scanned:** [count]
- **Patterns checked:** 18
- **Threats found:** [count]
- **Verdict:** CLEAN | LOW RISK | MEDIUM RISK | HIGH RISK
## Results Matrix
| # | Category | Pattern | Matches | Severity |
|---|----------|---------|---------|----------|
| 1 | Script tags | <script> | 0 | — |
| ... | ... | ... | ... | ... |
## Detailed Findings (if any)
| Severity | Category | File:Line | Content | Remediation |
|----------|----------|-----------|---------|-------------|
| P0/P1/P2/P3 | ... | ... | ... | ... |
## Sample File Review
- Files reviewed: [list]
- Structure: [description]
- Suspicious content: [none / details]
Ask user permission before saving:
"May I write the report to
docs/security/markdown-injection-scan-{YYYY-MM-DD}.md?"
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