New: 98,000+ skills indexed from GitHub repos with 100+ stars · every skill safety-checkedBrowse top skillsTop skills
Esc to closeBrowse all skills
Submit a skillBrowse skills
Submit a skillBrowse skills

Agent skill

Detecting Email Account Compromise

by mukul975 in mukul975/Anthropic-Cybersecurity-Skills

Detect compromised O365 and Google Workspace email accounts by analyzing Unified Audit Logs and Azure AD sign-in logs for impossible travel, inbox rule creation/deletion (Set-InboxRule…

Apache-2.0Auto-check passedBackend & APIs

Install Detecting Email Account Compromise

skills CLI
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill detecting-email-account-compromise -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills detecting-email-account-compromise --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/detecting-email-account-compromise .claude/skills/detecting-email-account-compromise && rm -rf skills-src

Use ~/.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/

Facts

Skill name
detecting-email-account-compromise
GitHub stars
34k
Token cost
~823 tokens
SKILL.md length
318 words
Files
4 (incl. scripts, references)
Skills in repo
644
Repo updated
First seen
Licence
Apache-2.0

At a glance

Detect compromised O365 and Google Workspace email accounts by analyzing Unified Audit Logs and Azure AD sign-in logs for impossible travel, inbox rule creation/deletion (Set-InboxRule…

  • Works in 9 steps: Export audit logs or connect to… → Query inbox rules for all monitored… → Analyze rules for external forwarding… → …
  • Investigating suspected business email compromise (BEC)
  • SKILL.md covers Overview, When to Use, Prerequisites and Steps, plus 1 more section
  • Runs Python scripts from its folder

What it does

Detecting Email Account Compromise is an agent skill from mukul975/Anthropic-Cybersecurity-Skills. Detect compromised O365 and Google Workspace email accounts by analyzing Unified Audit Logs and Azure AD sign-in logs for impossible travel, inbox rule creation/deletion (Set-InboxRule, New-InboxRule), external mail forwarding rules, and unusual Microsoft Graph API access or OAuth token use. Use when investigating suspected business email compromise (BEC), account takeover, or mailbox persistence via malicious inbox rules.

Its SKILL.md is about 820 tokens, which your agent loads only when the skill is triggered. The skill folder holds 5 other files, including scripts and reference files (for example `references/api-reference.md` and `scripts/agent.py`).

It sits in Backend & APIs, covering Email management, Cloud office suites and OAuth and OpenID Connect. It works with Microsoft 365, Microsoft Entra ID, Google Workspace and Python. 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

  • Investigating suspected business email compromise (BEC)
  • Account takeover
  • Mailbox persistence via malicious inbox rules

Example prompts

  • “/detecting-email-account-compromise”

Requirements

  • Python 3

Workflow steps

9 steps, taken from the first numbered list in SKILL.md.

  1. Export audit logs or connect to Microsoft Graph API using MSAL authentication
  2. Query inbox rules for all monitored mailboxes via /users/{id}/mailFolders/inbox/messageRules
  3. Analyze rules for external forwarding (ForwardTo, RedirectTo external addresses)
  4. Detect suspicious rule patterns: deletion rules, keyword-matching rules targeting financial terms
  5. Query sign-in logs via /auditLogs/signIns for unusual locations and impossible travel
  6. Check for suspicious user agent strings (python-requests, PowerShell, curl)
  7. Identify OAuth application consent grants for suspicious third-party apps
  8. Correlate findings across users to detect campaign-level compromise
  9. Generate compromise indicators report with severity scores

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 1 file 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

Detecting Email Account Compromise loads about 823 tokens when it runs, and up to ~1.4k if it reads all its reference files. Until then it costs about 115 tokens; SKILL.md has 318 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~115
When it runs · the whole SKILL.md, loaded when a task matches
~823
With references · SKILL.md plus every file in references/, read only if the agent opens them
~1.4k

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). 318 words, ~823 tokens.

Download SKILL.mdSave it as .claude/skills/detecting-email-account-compromise/SKILL.md (or your agent's skills folder). This skill also uses 3 other files; get the full folder from GitHub.
name
detecting-email-account-compromise
description
Detect compromised O365 and Google Workspace email accounts by analyzing Unified Audit Logs and Azure AD sign-in logs for impossible travel, inbox rule creation/deletion (Set-InboxRule, New-InboxRule), external mail forwarding rules, and unusual Microsoft Graph API access or OAuth token use. Use when investigating suspected business email compromise (BEC), account takeover, or mailbox persistence via malicious inbox rules.
domain
cybersecurity
subdomain
incident-response
tags
email-compromise, office365, microsoft-graph, bec, inbox-rules, sign-in-analysis, account-takeover
mitre_attack
T1486, T1490, T1070, T1078, T1566
version
1.0
author
mahipal
license
Apache-2.0
nist_csf
RS.MA-01, RS.MA-02, RS.AN-03, RC.RP-01

Detecting Email Account Compromise

Overview

Email account compromise (EAC) is a prevalent attack vector where adversaries gain unauthorized access to mailboxes to exfiltrate sensitive data, conduct business email compromise (BEC), or establish persistence through inbox rule manipulation. Attackers commonly create forwarding rules to siphon emails, delete rules to hide evidence, or use OAuth tokens for persistent access. Detection relies on analyzing Microsoft 365 Unified Audit Logs, Azure AD sign-in logs for impossible travel or suspicious locations, inbox rule creation events (Set-InboxRule, New-InboxRule), and Microsoft Graph API access patterns. Key indicators include forwarding rules to external addresses, rules that delete or move messages matching keywords like "invoice" or "payment", and sign-ins from unusual user agents such as python-requests.

When to Use

  • When investigating security incidents that require detecting email account compromise
  • 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

  • Microsoft 365 with Unified Audit Logging enabled
  • Azure AD P1/P2 for risk detection APIs
  • Python 3.9+ with requests, msal libraries
  • Microsoft Graph API application registration with Mail.Read, AuditLog.Read.All permissions
  • Understanding of OAuth2 client credential flows

Steps

  1. Export audit logs or connect to Microsoft Graph API using MSAL authentication
  2. Query inbox rules for all monitored mailboxes via /users/{id}/mailFolders/inbox/messageRules
  3. Analyze rules for external forwarding (ForwardTo, RedirectTo external addresses)
  4. Detect suspicious rule patterns: deletion rules, keyword-matching rules targeting financial terms
  5. Query sign-in logs via /auditLogs/signIns for unusual locations and impossible travel
  6. Check for suspicious user agent strings (python-requests, PowerShell, curl)
  7. Identify OAuth application consent grants for suspicious third-party apps
  8. Correlate findings across users to detect campaign-level compromise
  9. Generate compromise indicators report with severity scores

Expected Output

A JSON report listing compromised or suspicious accounts, malicious inbox rules detected, impossible travel events, suspicious OAuth grants, and recommended containment actions with severity ratings.

© 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 3 other files (scripts, references) in skills/detecting-email-account-compromise of mukul975/Anthropic-Cybersecurity-Skills.

  • SKILL.md
  • LICENSE
  • references/api-reference.md
  • scripts/agent.py

Open the folder on GitHubat commit 54a7988

Compare with similar skills

Detecting Email Account Compromise 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.

Detecting Email Account Compromise compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Detecting Email Account Compromise this skillmukul975/Anthropic-Cybersecurity-Skills34k—~823Automated safety check: PassApache-2.0
Google WorkspaceRedWoodOG/Hermes-Desktop177—~2.1kAutomated safety check: PassMIT
Community Google WorkspaceArgentAIOS/argentos-core126—~2.8kAutomated safety check: PassMIT
Google WorkspaceTommy-yw/RunbookHermes5461 repos~2.7kAutomated safety check: PassMIT
Google Workspaceericrisco/rsc-harness180—~3.2kAutomated safety check: PassMIT
GCP Workspace Pivotwgpsec/AboutSecurity1.8k—~2.9kAutomated safety check: PassNone

Similar skills

  • Google Workspace

    RedWoodOG/Hermes-Desktop

    Gmail, Calendar, Drive, Contacts, Sheets, and Docs integration via Python.

    177 GitHub stars~2.1k tokensUpdated 4 mo ago
    Backend & APIsAuto-check passed

  • Community Google Workspace

    ArgentAIOS/argentos-core

    Gmail, Calendar, Drive, Contacts, Sheets, and Docs integration for community skills.

    126 GitHub stars~2.8k tokensUpdated 3 mo ago
    Documents & OfficeAuto-check passed

  • Google Workspace

    Tommy-yw/RunbookHermes

    Gmail, Calendar, Drive, Contacts, Sheets, and Docs integration for Hermes.

    546 GitHub starsUsed in 1 repo~2.7k tokens
    Documents & OfficeAuto-check passed

  • Google Workspace

    ericrisco/rsc-harness

    A skill your agent uses when server-side code reads or writes Gmail, Drive, Calendar, or Sheets with a GCP service account and no human in the OAuth loop: picking the auth mode (app-owned vs…

    180 GitHub stars~3.2k tokensUpdated yesterday
    Backend & APIsAuto-check passed

  • GCP Workspace Pivot

    wgpsec/AboutSecurity

    GCP 到 Google Workspace 的穿越攻击方法论。当已获取 GCP Service Account 或 Project 权限并发现目标组织使用 Google Workspace、需要从云平台穿越到企业邮件/文档/管理控制台、或发现 Domain-Wide Delegation 配置时使用。覆盖 Domain-Wide Delegation 滥用、OAuth…

    1.8k GitHub stars~2.9k tokensUpdated yesterday
    Backend & APIsAuto-check passed

  • Pp Workspace Admin

    mvanhorn/printing-press-library

    GAT-style Google Workspace auditing as an agent-native CLI: sync Directory, Drive, Gmail, Reports, and Alert Center into a local store, then run offline cross-API audits, offboarding, and OAuth-app…

    2.1k GitHub stars~11k tokensUpdated yesterday
    Backend & APIsAuto-check: notes

More from mukul975/Anthropic-Cybersecurity-Skills

All 644 skills in this repo

  • Campaign 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.

    34k GitHub stars~2.3k tokensUpdated 1 mo ago
    Auto-check passed

  • 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.

    34k GitHub stars~2.8k tokensUpdated 1 mo ago
    Auto-check passed

  • 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.

    34k GitHub stars~2.8k tokensUpdated 1 mo ago
    Auto-check passed

  • 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.

    34k GitHub stars~1.2k tokensUpdated 1 mo ago
    Auto-check passed

  • 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.

    34k GitHub stars~2.7k tokensUpdated 1 mo ago
    Auto-check passed

  • 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.

    34k GitHub stars~2k tokensUpdated 1 mo ago
    Auto-check passed

Works with

Categories

Questions about Detecting Email Account Compromise

What does Detecting Email Account Compromise do?

Detect compromised O365 and Google Workspace email accounts by analyzing Unified Audit Logs and Azure AD sign-in logs for impossible travel, inbox rule creation/deletion (Set-InboxRule…. Detecting Email Account Compromise is an agent skill from mukul975/Anthropic-Cybersecurity-Skills. Detect compromised O365 and Google Workspace email accounts by analyzing Unified Audit Logs and Azure AD sign-in logs for impossible travel, inbox rule creation/deletion (Set-InboxRule, New-InboxRule), external mail forwarding rules, and unusual Microsoft Graph API access or OAuth token use.

When should I use Detecting Email Account Compromise?

Detecting Email Account Compromise fits situations like: investigating suspected business email compromise (BEC); account takeover; mailbox persistence via malicious inbox rules.

How do I install Detecting Email Account Compromise in Claude Code?

Run `npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill detecting-email-account-compromise -a claude-code`. Or copy the skill folder (skills/detecting-email-account-compromise in mukul975/Anthropic-Cybersecurity-Skills) into .claude/skills/detecting-email-account-compromise in your project. Claude Code loads it when a task matches its description.

How do I install Detecting Email Account Compromise in Codex?

Run `npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill detecting-email-account-compromise -a codex`. Or copy the skill folder (skills/detecting-email-account-compromise in mukul975/Anthropic-Cybersecurity-Skills) into .agents/skills/detecting-email-account-compromise in your project. Codex loads it when a task matches its description.

Can I use Detecting Email Account Compromise 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 detecting-email-account-compromise -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/detecting-email-account-compromise, .gemini/skills/detecting-email-account-compromise, .github/skills/detecting-email-account-compromise and .opencode/skills/detecting-email-account-compromise in your project.

What does Detecting Email Account Compromise need to run?

Going by SKILL.md and its folder, Detecting Email Account Compromise needs Python for the scripts in its folder. Our summary lists: Python 3.

Does Detecting Email Account Compromise 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 Detecting Email Account Compromise 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 Detecting Email Account Compromise use?

Detecting Email Account Compromise 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 Detecting Email Account Compromise use?

About 823 tokens (SKILL.md is roughly 3.3k 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 619 tokens, read only when the agent opens those files.

What are the alternatives to Detecting Email Account Compromise?

Skills that share tags, products or a category with Detecting Email Account Compromise: Google Workspace (RedWoodOG/Hermes-Desktop, 177 stars), Community Google Workspace (ArgentAIOS/argentos-core, 126 stars), Google Workspace (Tommy-yw/RunbookHermes, 546 stars) and Google Workspace (ericrisco/rsc-harness, 180 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Detecting Email Account Compromise?

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.