网络安全 Analyzing Indicators Of Compromise

Analyzing Indicators Of Compromise：网络安全 skill: analyzing-indicators-of-compromise，适用于安全分析、取证与威胁排查场景。

Skill Documentation

网络安全 Analyzing Indicators Of Compromise

摘要

Analyzing Indicators Of Compromise：网络安全 skill: analyzing-indicators-of-compromise，适用于安全分析、取证与威胁排查场景。

> 来源: mukul975/Anthropic-Cybersecurity-Skills (18k stars) — 网络安全专业技能集

> 原文件: skills/analyzing-indicators-of-compromise/SKILL.md

> 模型推荐: claude-opus-4-7 (安全分析深度推理)

这个 skill 是干嘛的

mukul975 整理的 100+ 个网络安全专业 skill,覆盖渗透测试 / 取证 / 威胁情报 / 合规审计 / 云安全 / 移动安全 等领域。每个 skill 对应一个具体的安全分析任务。

michael 强调"skill 要有相应的指导功能,指导用户使用",所以加了下面两节让 Agent 和用户对接。

---

🤖 Agent 使用说明

1. 用户提到"分析 X 日志 / 取证 / 检测威胁 / 渗透测试 / 安全审计"时,触发对应 skill

2. skill 会按操作步骤一步步执行(取证镜像 / 解析日志 / 跑威胁情报 / etc.)

3. 涉及破坏性操作(rm/drop/format)前必须 ask user 确认

4. 完工后让 Agent 跑自检 step

5. 如果用户要求做"防御性分析" — 区分恶意代码审计 vs 渗透测试

👤 用户需要做什么?

1. 告诉 Agent 你要做什么(分析日志 / 取证 / 安全审计 / 渗透测试)

2. 如果需要提供文件/镜像/日志/哈希,按 Agent 提示提供

3. 涉及破坏性操作时明确告诉 Agent"继续"或"取消"

4. 全程 Agent 自动化,你只需提供数据 + 回答决策点

---

原 skill 内容(mukul975/Anthropic-Cybersecurity-Skills/skills/analyzing-indicators-of-compromise/SKILL.md,截断到 12k chars)

---

name: analyzing-indicators-of-compromise

description: 'Analyzes indicators of compromise (IOCs) including IP addresses, domains,

file hashes, URLs, and email artifacts to determine maliciousness confidence, campaign

attribution, and blocking priority. Use when triaging IOCs from phishing emails,

security alerts, or external threat feeds; enriching raw IOCs with multi-source

intelligence; or making block/monitor/whitelist decisions. Activates for requests

involving VirusTotal, AbuseIPDB, MalwareBazaar, MISP, or IOC enrichment pipelines.

'

domain: cybersecurity

subdomain: threat-intelligence

tags:

• IOC
• VirusTotal
• AbuseIPDB
• MalwareBazaar
• MISP
• threat-intelligence
• STIX
• NIST-CSF

version: 1.0.0

author: mahipal

license: Apache-2.0

atlas_techniques:

• AML.T0052

nist_csf:

• ID.RA-01
• ID.RA-05
• DE.CM-01
• DE.AE-02

mitre_attack:

• T1071
• T1105
• T1041
• T1567

mitre_f3:

version: '1.1'

tactics:

• reconnaissance
• resource-development
• initial-access

techniques:

• id: T1598

name: Phishing for Information

tactic: reconnaissance

source: attack

• id: T1660

name: Phishing

tactic: initial-access

source: attack

• id: T1583.001

name: 'Acquire Infrastructure: Domains'

tactic: resource-development

source: attack

• id: F1020.002

name: 'Create Fake Materials: Fake Website'

tactic: resource-development

source: f3

---

Analyzing Indicators of Compromise

When to Use

Use this skill when:

• A phishing email or alert generates IOCs (URLs, IP addresses, file hashes) requiring rapid triage
• Automated feeds deliver bulk IOCs that need confidence scoring before ingestion into blocking controls
• An incident investigation requires contextual enrichment of observed network artifacts

**Do not use** this skill in isolation for high-stakes blocking decisions — always combine automated enrichment with analyst judgment, especially for shared infrastructure (CDNs, cloud providers).

Prerequisites

• VirusTotal API key (free or Enterprise) for multi-AV and sandbox lookup
• AbuseIPDB API key for IP reputation checks
• MISP instance or TIP for cross-referencing against known campaigns
• Python with `requests` and `vt-py` libraries, or SOAR platform with pre-built connectors

Workflow

Step 1: Normalize and Classify IOC Types

Before enriching, classify each IOC:

• **IPv4/IPv6 address**: Check if RFC 1918 private (skip external enrichment), validate format
• **Domain/FQDN**: Defang for safe handling (`evil[.]com`), extract registered domain via tldextract
• **URL**: Extract domain + path separately; check for redirectors
• **File hash**: Identify hash type (MD5/SHA-1/SHA-256); prefer SHA-256 for uniqueness
• **Email address**: Split into domain (check MX/DMARC) and local part for pattern analysis

Defang IOCs in documentation (replace `.` with `[.]` and `://` with `[://]`) to prevent accidental clicks.

Step 2: Multi-Source Enrichment

**VirusTotal (file hash, URL, IP, domain)**:

import vt

client = vt.Client("YOUR_VT_API_KEY")

# File hash lookup
file_obj = client.get_object(f"/files/{sha256_hash}")
detections = file_obj.last_analysis_stats
print(f"Malicious: {detections['malicious']}/{sum(detections.values())}")

# Domain analysis
domain_obj = client.get_object(f"/domains/{domain}")
print(domain_obj.last_analysis_stats)
print(domain_obj.reputation)
client.close()

**AbuseIPDB (IP addresses)**:

import requests

response = requests.get(
    "https://api.abuseipdb.com/api/v2/check",
    headers={"Key": "YOUR_KEY", "Accept": "application/json"},
    params={"ipAddress": "1.2.3.4", "maxAgeInDays": 90}
)
data = response.json()["data"]
print(f"Confidence: {data['abuseConfidenceScore']}%, Reports: {data['totalReports']}")

**MalwareBazaar (file hashes)**:

response = requests.post(
    "https://mb-api.abuse.ch/api/v1/",
    data={"query": "get_info", "hash": sha256_hash}
)
result = response.json()
if result["query_status"] == "ok":
    print(result["data"][0]["tags"], result["data"][0]["signature"])

Step 3: Contextualize with Campaign Attribution

Query MISP for existing events matching the IOC:

from pymisp import PyMISP

misp = PyMISP("https://misp.example.com", "API_KEY")
results = misp.search(value="evil-domain.com", type_attribute="domain")
for event in results:
    print(event["Event"]["info"], event["Event"]["threat_level_id"])

Check Shodan for IP context (hosting provider, open ports, banners) to identify if the IP belongs to bulletproof hosting or a legitimate cloud provider (false positive risk).

Step 4: Assign Confidence Score and Disposition

Apply a tiered decision framework:

• **Block (High Confidence ≥ 70%)**: ≥15 AV detections on VT, AbuseIPDB score ≥70, matches known malware family or campaign
• **Monitor/Alert (Medium 40–69%)**: 5–14 AV detections, moderate AbuseIPDB score, no campaign attribution
• **Whitelist/Investigate (Low <40%)**: ≤4 AV detections, no abuse reports, legitimate service (Google, Cloudflare CDN IPs)
• **False Positive**: Legitimate business service incorrectly flagged; document and exclude from future alerts

Step 5: Document and Distribute

Record findings in TIP/MISP with:

• All enrichment data collected (timestamps, source, score)
• Disposition decision and rationale
• Blocking actions taken (firewall, proxy, DNS sinkhole)
• Related incident ticket number

Export to STIX indicator object with confidence field set appropriately.

Key Concepts

| Term | Definition |

|------|-----------|

| **IOC** | Indicator of Compromise — observable network or host artifact indicating potential compromise |

| **Enrichment** | Process of adding contextual data to a raw IOC from multiple intelligence sources |

| **Defanging** | Modifying IOCs (replacing `.` with `[.]`) to prevent accidental activation in documentation |

| **False Positive Rate** | Percentage of benign artifacts incorrectly flagged as malicious; critical for tuning block thresholds |

| **Sinkhole** | DNS server redirecting malicious domain lookups to a benign IP for detection without blocking traffic entirely |

| **TTL** | Time-to-live for an IOC in blocking controls; IP indicators should expire after 30 days, domains after 90 days |

Tools & Systems

• **VirusTotal**: Multi-engine malware scanner and threat intelligence platform with 70+ AV engines, sandbox reports, and community comments
• **AbuseIPDB**: Community-maintained IP reputation database with 90-day abuse report history
• **MalwareBazaar (abuse.ch)**: Free malware hash repository with YARA rule associations and malware family tagging
• **URLScan.io**: Free URL analysis service that captures screenshots, DOM, and network requests for phishing URL triage
• **Shodan**: Internet-wide scan data providing hosting provider, open ports, and banner information for IP enrichment

Common Pitfalls

• **Blocking shared infrastructure**: CDN IPs (Cloudflare 104.21.x.x, AWS CloudFront) may legitimately host malicious content but blocking the IP disrupts thousands of legitimate sites.
• **VT score obsession**: Low VT detection count does not mean benign — zero-day malware and custom APT tools often score 0 initially. Check sandbox behavior, MISP, and passive DNS.
• **Missing defanging**: Pasting live IOCs in emails or Confluence docs can trigger automated URL scanners or phishing tools.
• **No expiration policy**: IOCs without TTLs accumulate in blocklists indefinitely, generating false positives as infrastructure is repurposed by legitimate users.
• **Over-relying on single source**: VirusTotal aggregates AV opinions — all may be wrong or lag behind emerging malware. Use 3+ independent sources for high-stakes decisions.

常见问题（FAQ）

使用「Analyzing Indi」这个 skill 能解决什么问题?

本 skill 专注于Analyzing Indi，网络安全 skill: analyzing-indicators-of-compromise。它将相关流程标准化，帮助用户更快拿到可靠结果，减少重复手工操作。

什么情况下适合使用「Analyzing Indi」?

当你需要在Analyzing Indicators Of Compromise相关工作中获得稳定、可复用的产出时最适合——无论是单次任务还是纳入日常工作流，都能直接调用。

使用「Analyzing Indi」前需要准备什么?

需要明确授权范围内的目标系统或样本文件，并准备隔离的分析环境（虚拟机/沙箱）。