Incident Triage
briiirussell/cybersecurity-skills
Guide rapid triage and initial response to security incidents following NIST SP 800-61 methodology.
Runs a hypothesis-driven threat hunt for web shell deployment (T1505.003) on internet-facing servers by analyzing file creation in web directories, suspicious child-process spawning from web server…
Install Hunting For Webshell Activity
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill hunting-for-webshell-activity -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills hunting-for-webshell-activity --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/hunting-for-webshell-activity .claude/skills/hunting-for-webshell-activity && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "hunting-for-webshell-activity" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/hunting-for-webshell-activity into .claude/skills/hunting-for-webshell-activity/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "hunting-for-webshell-activity", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/hunting-for-webshell-activityType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill hunting-for-webshell-activity -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills hunting-for-webshell-activity --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/hunting-for-webshell-activity .agents/skills/hunting-for-webshell-activity && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "hunting-for-webshell-activity" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/hunting-for-webshell-activity into .agents/skills/hunting-for-webshell-activity/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "hunting-for-webshell-activity", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill hunting-for-webshell-activity -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills hunting-for-webshell-activity --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/hunting-for-webshell-activity .cursor/skills/hunting-for-webshell-activity && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "hunting-for-webshell-activity" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/hunting-for-webshell-activity into .cursor/skills/hunting-for-webshell-activity/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "hunting-for-webshell-activity", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git --path skills/hunting-for-webshell-activity--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill hunting-for-webshell-activity -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills hunting-for-webshell-activity --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/hunting-for-webshell-activity .gemini/skills/hunting-for-webshell-activity && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "hunting-for-webshell-activity" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/hunting-for-webshell-activity into .gemini/skills/hunting-for-webshell-activity/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "hunting-for-webshell-activity", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills hunting-for-webshell-activityInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill hunting-for-webshell-activity -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/hunting-for-webshell-activity .github/skills/hunting-for-webshell-activity && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "hunting-for-webshell-activity" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/hunting-for-webshell-activity into .github/skills/hunting-for-webshell-activity/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "hunting-for-webshell-activity", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill hunting-for-webshell-activity -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills hunting-for-webshell-activity --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/hunting-for-webshell-activity .opencode/skills/hunting-for-webshell-activity && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "hunting-for-webshell-activity" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/hunting-for-webshell-activity into .opencode/skills/hunting-for-webshell-activity/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "hunting-for-webshell-activity", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
hunting-for-webshell-activity- GitHub stars
- 34k
- Token cost
- ~904 tokens
- SKILL.md length
- 295 words
- Files
- 8 (incl. scripts, references, assets)
- Skills in repo
- 644
- Repo updated
- First seen
- Licence
- Apache-2.0
At a glance
Runs a hypothesis-driven threat hunt for web shell deployment (T1505.003) on internet-facing servers by analyzing file creation in web directories, suspicious child-process spawning from web server…
- Works in 7 steps: Formulate Hypothesis: Define a testable… → Identify Data Sources: Determine which… → Execute Queries: Run detection queries… → …
- Hunting for web shells after a public-facing app compromise
- SKILL.md covers When to Use, Prerequisites, Workflow and Key Concepts, plus 3 more sections
- Runs Python scripts from its folder
What it does
Hunting For Webshell Activity is an agent skill from mukul975/Anthropic-Cybersecurity-Skills. Runs a hypothesis-driven threat hunt for web shell deployment (T1505.003) on internet-facing servers by analyzing file creation in web directories, suspicious child-process spawning from web server processes, and anomalous HTTP request patterns. Use when hunting for web shells after a public-facing app compromise, when EDR/SIEM alerts fire on webserver process anomalies, or during incident response on internet-facing infrastructure.
Its SKILL.md is about 900 tokens, which your agent loads only when the skill is triggered. The skill folder holds 10 other files, including scripts, reference files and assets (for example `assets/template.md`, `references/api-reference.md` and `references/standards.md`).
It sits in Security, covering Security operations and Incident response. The repository describes itself as: 817 structured cybersecurity skills for AI agents · Mapped to 6 frameworks: MITRE ATT&CK, NIST CSF 2.0, MITRE ATLAS, D3FEND, NIST AI RMF & MITRE F3 (Fight Fraud) · agentskills.io…. The licence is Apache-2.0.
When your agent uses it
- Hunting for web shells after a public-facing app compromise
- EDR/SIEM alerts fire on webserver process anomalies
- During incident response on internet-facing infrastructure
Example prompts
- “/hunting-for-webshell-activity”
Requirements
- Python 3
Workflow steps
7 steps, taken from the first numbered list in SKILL.md.
- Formulate Hypothesis: Define a testable hypothesis based on threat intelligence or ATT&CK gap analysis.
- Identify Data Sources: Determine which logs and telemetry are needed to validate or refute the hypothesis.
- Execute Queries: Run detection queries against SIEM and EDR platforms to collect relevant events.
- Analyze Results: Examine query results for anomalies, correlating across multiple data sources.
- Validate Findings: Distinguish true positives from false positives through contextual analysis.
- Correlate Activity: Link findings to broader attack chains and threat actor TTPs.
- Document and Report: Record findings, update detection rules, and recommend response actions.
What it can do on your machine
Read from SKILL.md and the folder at commit 54a7988. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Ships 2 files in scripts/ (Python), which the agent can run.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Hunting For Webshell Activity loads about 904 tokens when it runs, and up to ~2.5k if it reads all its reference files. Until then it costs about 117 tokens; SKILL.md has 295 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.
SKILL.md
The full file from mukul975/Anthropic-Cybersecurity-Skills at commit 54a7988, republished under its Apache-2.0 licence (© mukul975). 295 words, ~904 tokens.
Download SKILL.mdSave it as
.claude/skills/hunting-for-webshell-activity/SKILL.md (or your agent's skills folder). This skill also uses 7 other files; get the full folder from GitHub.- name
- hunting-for-webshell-activity
- description
- Runs a hypothesis-driven threat hunt for web shell deployment (T1505.003) on internet-facing servers by analyzing file creation in web directories, suspicious child-process spawning from web server processes, and anomalous HTTP request patterns. Use when hunting for web shells after a public-facing app compromise, when EDR/SIEM alerts fire on webserver process anomalies, or during incident response on internet-facing infrastructure.
- domain
- cybersecurity
- subdomain
- threat-hunting
- tags
- threat-hunting, mitre-attack, webshell, persistence, web-server, t1505, proactive-detection
- version
- 1.0
- author
- mahipal
- license
- Apache-2.0
- d3fend_techniques
- Executable Denylisting, Execution Isolation, File Metadata Consistency Validation, Restore Access, Process Termination
- nist_csf
- DE.CM-01, DE.AE-02, DE.AE-07, ID.RA-05
- mitre_attack
- T1046, T1057, T1082, T1083, T1547
Hunting For Webshell Activity
When to Use
- When proactively hunting for indicators of hunting for webshell activity in the environment
- After threat intelligence indicates active campaigns using these techniques
- During incident response to scope compromise related to these techniques
- When EDR or SIEM alerts trigger on related indicators
- During periodic security assessments and purple team exercises
Prerequisites
- EDR platform with process and network telemetry (CrowdStrike, MDE, SentinelOne)
- SIEM with relevant log data ingested (Splunk, Elastic, Sentinel)
- Sysmon deployed with comprehensive configuration
- Windows Security Event Log forwarding enabled
- Threat intelligence feeds for IOC correlation
Workflow
- Formulate Hypothesis: Define a testable hypothesis based on threat intelligence or ATT&CK gap analysis.
- Identify Data Sources: Determine which logs and telemetry are needed to validate or refute the hypothesis.
- Execute Queries: Run detection queries against SIEM and EDR platforms to collect relevant events.
- Analyze Results: Examine query results for anomalies, correlating across multiple data sources.
- Validate Findings: Distinguish true positives from false positives through contextual analysis.
- Correlate Activity: Link findings to broader attack chains and threat actor TTPs.
- Document and Report: Record findings, update detection rules, and recommend response actions.
Key Concepts
| Concept | Description |
|---|---|
| T1505.003 | Web Shell |
| T1190 | Exploit Public-Facing Application |
| T1059.001 | PowerShell |
Tools & Systems
| Tool | Purpose |
|---|---|
| CrowdStrike Falcon | EDR telemetry and threat detection |
| Microsoft Defender for Endpoint | Advanced hunting with KQL |
| Splunk Enterprise | SIEM log analysis with SPL queries |
| Elastic Security | Detection rules and investigation timeline |
| Sysmon | Detailed Windows event monitoring |
| Velociraptor | Endpoint artifact collection and hunting |
| Sigma Rules | Cross-platform detection rule format |
Common Scenarios
- Scenario 1: China Chopper web shell via IIS vulnerability
- Scenario 2: ASPXSpy through vulnerable upload
- Scenario 3: PHP shell hidden in image file
- Scenario 4: JSP shell via Tomcat manager console
Output Format
Hunt ID: TH-HUNTIN-[DATE]-[SEQ]
Technique: T1505.003
Host: [Hostname]
User: [Account context]
Evidence: [Log entries, process trees, network data]
Risk Level: [Critical/High/Medium/Low]
Confidence: [High/Medium/Low]
Recommended Action: [Containment, investigation, monitoring]© mukul975, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 7 other files (scripts, references, assets) in skills/hunting-for-webshell-activity of mukul975/Anthropic-Cybersecurity-Skills.
- SKILL.md
- LICENSE
- assets/template.md
- references/api-reference.md
- references/standards.md
- references/workflows.md
- scripts/agent.py
- scripts/process.py
Open the folder on GitHubat commit 54a7988
Compare with similar skills
Hunting For Webshell Activity next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Hunting For Webshell Activity this skillmukul975/Anthropic-Cybersecurity-Skills | 34k | — | ~904 | Automated safety check: Pass | Apache-2.0 | |
| Incident Triagebriiirussell/cybersecurity-skills | 413 | — | ~1.5k | Automated safety check: Notes | MIT | |
| Breach Detection Systemmukul975/Privacy-Data-Protection-Skills | 301 | — | ~3k | Automated safety check: Pass | Apache-2.0 | |
| Sentinelvinayaklatthe/microsoft-security-skills | 175 | — | ~2.2k | Automated safety check: Pass | MIT | |
| Msp HelpdeskRTFM-IT-Services-LLC/msp-claude-skills | 115 | — | ~3.3k | Automated safety check: Pass | Custom licence | |
| Forensics OsqueryAgentSecOps/SecOpsAgentKit | 220 | 1 repos | ~4.9k | Automated safety check: Notes | Custom licence |
Similar skills
Breach Detection System
mukul975/Privacy-Data-Protection-Skills
Implements technical breach detection capabilities including SIEM integration, DLP alert configuration, anomaly detection rules, and insider threat monitoring.
Sentinel
vinayaklatthe/microsoft-security-skills
Guidance for designing and operating Microsoft Sentinel, the cloud-native SIEM and SOAR delivered through the Defender portal.
Msp Helpdesk
RTFM-IT-Services-LLC/msp-claude-skills
A skill your agent uses for anything about how your MSP runs day-to-day support: setting or questioning a ticket's priority, response and resolution targets, "the client says everything is down"…
Forensics Osquery
AgentSecOps/SecOpsAgentKit
SQL-powered forensic investigation and system interrogation using osquery to query operating systems as relational databases.
Ir Velociraptor
AgentSecOps/SecOpsAgentKit
Endpoint visibility, digital forensics, and incident response using Velociraptor Query Language (VQL) for evidence collection and threat hunting at scale.
More from mukul975/Anthropic-Cybersecurity-Skills
All 644 skills in this repoCampaign Attribution Evidence Analysis
mukul975/Anthropic-Cybersecurity-Skills
Weighs infrastructure, TTP, malware code and timing evidence with the Diamond Model and competing hypotheses to reach a confidence-rated attribution.
Go Malware Analysis in Ghidra
mukul975/Anthropic-Cybersecurity-Skills
Walks through reverse engineering Go-compiled malware in Ghidra: parsing buildinfo and pclntab, recovering stripped function names and extracting dependencies.
LNK and Jump List Forensics
mukul975/Anthropic-Cybersecurity-Skills
Guides forensic analysis of Windows LNK shortcut files and Jump Lists with LECmd, JLECmd and manual parsing to show file access and program execution.
Malware Persistence Analysis with Autoruns
mukul975/Anthropic-Cybersecurity-Skills
Hunts Windows malware persistence with Sysinternals Autoruns, covering run keys, services, scheduled tasks and drivers, with baseline comparison.
NTFS MFT Deleted File Recovery
mukul975/Anthropic-Cybersecurity-Skills
Guides a Windows forensic examination of the NTFS Master File Table to recover deleted-file evidence, build timelines and spot timestomping.
Network Covert Channel Analysis
mukul975/Anthropic-Cybersecurity-Skills
Detects DNS tunneling, ICMP exfiltration and HTTP-based covert channels in packet captures and DNS logs when hunting for hidden command-and-control traffic.
Related
Categories
Questions about Hunting For Webshell Activity
What does Hunting For Webshell Activity do?
Runs a hypothesis-driven threat hunt for web shell deployment (T1505.003) on internet-facing servers by analyzing file creation in web directories, suspicious child-process spawning from web server…. Hunting For Webshell Activity is an agent skill from mukul975/Anthropic-Cybersecurity-Skills.003) on internet-facing servers by analyzing file creation in web directories, suspicious child-process spawning from web server processes, and anomalous HTTP request patterns.
When should I use Hunting For Webshell Activity?
Hunting For Webshell Activity fits situations like: hunting for web shells after a public-facing app compromise; EDR/SIEM alerts fire on webserver process anomalies; during incident response on internet-facing infrastructure.
How do I install Hunting For Webshell Activity in Claude Code?
Run `npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill hunting-for-webshell-activity -a claude-code`. Or copy the skill folder (skills/hunting-for-webshell-activity in mukul975/Anthropic-Cybersecurity-Skills) into .claude/skills/hunting-for-webshell-activity in your project. Claude Code loads it when a task matches its description.
How do I install Hunting For Webshell Activity in Codex?
Run `npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill hunting-for-webshell-activity -a codex`. Or copy the skill folder (skills/hunting-for-webshell-activity in mukul975/Anthropic-Cybersecurity-Skills) into .agents/skills/hunting-for-webshell-activity in your project. Codex loads it when a task matches its description.
Can I use Hunting For Webshell Activity in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill hunting-for-webshell-activity -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/hunting-for-webshell-activity, .gemini/skills/hunting-for-webshell-activity, .github/skills/hunting-for-webshell-activity and .opencode/skills/hunting-for-webshell-activity in your project.
What does Hunting For Webshell Activity need to run?
Going by SKILL.md and its folder, Hunting For Webshell Activity needs Python for the scripts in its folder. Our summary lists: Python 3.
Does Hunting For Webshell Activity access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Hunting For Webshell Activity safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.
What licence does Hunting For Webshell Activity use?
Hunting For Webshell Activity is published under the Apache-2.0 licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Hunting For Webshell Activity use?
About 904 tokens (SKILL.md is roughly 3.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1.6k tokens, read only when the agent opens those files.
What are the alternatives to Hunting For Webshell Activity?
Skills that share tags, products or a category with Hunting For Webshell Activity: Incident Triage (briiirussell/cybersecurity-skills, 413 stars), Breach Detection System (mukul975/Privacy-Data-Protection-Skills, 301 stars), Sentinel (vinayaklatthe/microsoft-security-skills, 175 stars) and Msp Helpdesk (RTFM-IT-Services-LLC/msp-claude-skills, 115 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Hunting For Webshell Activity?
mukul975 (a GitHub user) maintains it in mukul975/Anthropic-Cybersecurity-Skills, which has 34,116 GitHub stars. The repository holds 644 skills in this directory. The repository was last updated on August 31, 2026.
Source: mukul975/Anthropic-Cybersecurity-Skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.