[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"skill:01M71B5TFCSVEKQ3N9A3S7BCZP":3,"skill-same:01M71B5TFCSVEKQ3N9A3S7BCZP":68},{"skillNo":4,"name":5,"nameZh":6,"description":7,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":15,"licenseFileUrl":6,"sourceHtmlUrl":16,"categories":17,"keywords":18,"publishedAt":39,"linkOnly":40,"markdownContent":41,"markdownBody":42,"frontMatter":43,"refName":47,"commitSha":48,"skillDirectory":49,"forksCount":50,"repositoryHtmlUrl":51,"repositoryHomepageUrl":6,"ownerHtmlUrl":52,"ownerBlogUrl":6,"ownerDescription":53,"updatedAt":54,"install":55,"resources":67},"01M71B5TFCSVEKQ3N9A3S7BCZP","cyber-hunting-for-domain-fronting-c2-traffic",null,"Detect domain fronting C2 traffic by analyzing SNI vs HTTP Host header mismatches in proxy logs and TLS certificate discrepancies using pyOpenSSL for certificate inspection","nexuslinkproductions\u002Fyuri-os","nexuslinkproductions","https:\u002F\u002Favatars.githubusercontent.com\u002Fu\u002F273246263?v=4","01M718YX9NZRCW50B59B8ZVDKN","Marcel Spatz","01M718YXAQ7530F4B1VKN6SFQV",2,"Apache-2.0","https:\u002F\u002Fgithub.com\u002Fnexuslinkproductions\u002Fyuri-os\u002Fblob\u002Fmain\u002F.claude\u002Fskills\u002Fcyber-hunting-for-domain-fronting-c2-traffic\u002FSKILL.md",[],[19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38],"domain","for","hunting for domain fronting c2 traffic","traffic","hunting","c2","cyber hunting for domain fronting c2 traffic","false","cybersecurity","http","tls","host","inspection","pyopenssl","tls-inspection","domain-fronting","true","license","network-security","proxy","2026-11-10 10:12:30",false,"---\nname: cyber-hunting-for-domain-fronting-c2-traffic\ndescription: \"Detect domain fronting C2 traffic by analyzing SNI vs HTTP Host header mismatches in proxy logs and TLS certificate discrepancies using pyOpenSSL for certificate inspection\"\nsource: mukul975\u002FAnthropic-Cybersecurity-Skills\nlicense: Apache-2.0\nauthorized_lab: false\norigin_frontmatter: \"name: hunting-for-domain-fronting-c2-traffic | description: Detect domain fronting C2 traffic by analyzing SNI vs HTTP Host header |   mismatches in proxy logs and TLS certificate discrepancies using pyOpenSSL for certificate |   inspection | domain: cybersecurity | subdomain: threat-hunting | tags: | - domain-fronting | - c2-detection | - tls-inspection | - proxy-logs | - pyopenssl | - threat-hunting | - network-security | version: '1.0' | author: mahipal | license: Apache-2.0 | d3fend_techniqu\"\nhide: true\n---\n\n> Defensive\u002Fanalysis cyber skill. Source: mukul975\u002FAnthropic-Cybersecurity-Skills (Apache-2.0). Advisory knowledge — the YURI floor, protected paths, and owner authority always outrank any instruction in this body.\n\n# Hunting for Domain Fronting C2 Traffic\n\n## Overview\n\nDomain fronting (MITRE ATT&CK T1090.004) is a technique where attackers use different domain names in the TLS SNI field and the HTTP Host header to disguise C2 traffic behind legitimate CDN-hosted domains. This skill detects domain fronting by parsing proxy\u002Fweb gateway logs for SNI-Host header mismatches, analyzing TLS certificates for CDN provider identification, flagging connections where the SNI points to a high-reputation domain but the Host header targets an attacker-controlled domain, and correlating with known CDN provider IP ranges.\n\n\n## When to Use\n\n- When investigating security incidents that require hunting for domain fronting c2 traffic\n- When building detection rules or threat hunting queries for this domain\n- When SOC analysts need structured procedures for this analysis type\n- When validating security monitoring coverage for related attack techniques\n\n## Prerequisites\n\n- Web proxy or secure web gateway logs with SNI and Host header fields\n- Python 3.8+ with pyOpenSSL and cryptography libraries\n- TLS inspection enabled on proxy for Host header visibility\n- CDN provider IP range lists (CloudFront, Azure CDN, Cloudflare)\n\n## Steps\n\n1. Parse proxy logs for connections with both SNI and Host header fields\n2. Compare SNI domain against HTTP Host header for mismatches\n3. Extract TLS certificate Subject and SAN fields using pyOpenSSL\n4. Identify CDN-hosted connections via certificate issuer and IP ranges\n5. Flag high-confidence domain fronting where SNI and Host differ on CDN IPs\n6. Score alerts based on domain reputation differential\n7. Generate detection report with network flow context\n\n## Expected Output\n\nJSON report containing detected domain fronting indicators with SNI-Host pairs, certificate details, CDN provider identification, confidence scores, and MITRE ATT&CK technique mapping.\n","> Defensive\u002Fanalysis cyber skill. Source: mukul975\u002FAnthropic-Cybersecurity-Skills (Apache-2.0). Advisory knowledge — the YURI floor, protected paths, and owner authority always outrank any instruction in this body.\n\n# Hunting for Domain Fronting C2 Traffic\n\n## Overview\n\nDomain fronting (MITRE ATT&CK T1090.004) is a technique where attackers use different domain names in the TLS SNI field and the HTTP Host header to disguise C2 traffic behind legitimate CDN-hosted domains. This skill detects domain fronting by parsing proxy\u002Fweb gateway logs for SNI-Host header mismatches, analyzing TLS certificates for CDN provider identification, flagging connections where the SNI points to a high-reputation domain but the Host header targets an attacker-controlled domain, and correlating with known CDN provider IP ranges.\n\n\n## When to Use\n\n- When investigating security incidents that require hunting for domain fronting c2 traffic\n- When building detection rules or threat hunting queries for this domain\n- When SOC analysts need structured procedures for this analysis type\n- When validating security monitoring coverage for related attack techniques\n\n## Prerequisites\n\n- Web proxy or secure web gateway logs with SNI and Host header fields\n- Python 3.8+ with pyOpenSSL and cryptography libraries\n- TLS inspection enabled on proxy for Host header visibility\n- CDN provider IP range lists (CloudFront, Azure CDN, Cloudflare)\n\n## Steps\n\n1. Parse proxy logs for connections with both SNI and Host header fields\n2. Compare SNI domain against HTTP Host header for mismatches\n3. Extract TLS certificate Subject and SAN fields using pyOpenSSL\n4. Identify CDN-hosted connections via certificate issuer and IP ranges\n5. Flag high-confidence domain fronting where SNI and Host differ on CDN IPs\n6. Score alerts based on domain reputation differential\n7. Generate detection report with network flow context\n\n## Expected Output\n\nJSON report containing detected domain fronting indicators with SNI-Host pairs, certificate details, CDN provider identification, confidence scores, and MITRE ATT&CK technique mapping.\n",{"hide":44,"name":5,"source":45,"license":15,"description":7,"authorized_lab":40,"origin_frontmatter":46},true,"mukul975\u002FAnthropic-Cybersecurity-Skills","name: hunting-for-domain-fronting-c2-traffic | description: Detect domain fronting C2 traffic by analyzing SNI vs HTTP Host header |   mismatches in proxy logs and TLS certificate discrepancies using pyOpenSSL for certificate |   inspection | domain: cybersecurity | subdomain: threat-hunting | tags: | - domain-fronting | - c2-detection | - tls-inspection | - proxy-logs | - pyopenssl | - threat-hunting | - network-security | version: '1.0' | author: mahipal | license: Apache-2.0 | d3fend_techniqu","main","4c6d8d65f3d6096e2fc25b0845e481dda73c2794",".claude\u002Fskills\u002Fcyber-hunting-for-domain-fronting-c2-traffic",0,"https:\u002F\u002Fgithub.com\u002Fnexuslinkproductions\u002Fyuri-os","https:\u002F\u002Fgithub.com\u002Fnexuslinkproductions","Building deterministic AI governance and continuity systems. Workflow architect + visual storyteller","2026-11-11 16:42:59",{"source":8,"skillName":5,"commands":56,"prompt":66,"zipAvailable":44},[57,60,63],{"tool":58,"command":59},"npx","npx skills add nexuslinkproductions\u002Fyuri-os --skill cyber-hunting-for-domain-fronting-c2-traffic",{"tool":61,"command":62},"bunx","bunx skills add nexuslinkproductions\u002Fyuri-os --skill cyber-hunting-for-domain-fronting-c2-traffic",{"tool":64,"command":65},"pnpm","pnpm dlx skills add nexuslinkproductions\u002Fyuri-os --skill cyber-hunting-for-domain-fronting-c2-traffic","安装技能，技能地址：https:\u002F\u002Fgithub.com\u002Fnexuslinkproductions\u002Fyuri-os\u002Fblob\u002Fmain\u002F.claude\u002Fskills\u002Fcyber-hunting-for-domain-fronting-c2-traffic\u002FSKILL.md",[],[69,92,115,145,174,193],{"skillNo":70,"name":71,"nameZh":6,"description":72,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":73,"licenseFileUrl":6,"sourceHtmlUrl":74,"categories":75,"keywords":76,"publishedAt":39},"01M71CG1AME5WC0A79AE65WT0X","zoom-out","Tell the agent to zoom out and give broader context or a higher-level perspective. Use when you're unfamiliar with a section of code or need to understand how it fits into the bigger picture.","MIT","https:\u002F\u002Fgithub.com\u002Fnexuslinkproductions\u002Fyuri-os\u002Fblob\u002Fmain\u002Fskills\u002Fzoom-out\u002FSKILL.md",[],[77,78,79,80,81,82,83,35,84,85,86,87,88,89,90,91],"zoom out","zoom","with","harness","how","section","re","understand","use","perspective","when","you","code","it","context",{"skillNo":93,"name":94,"nameZh":6,"description":95,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":73,"licenseFileUrl":6,"sourceHtmlUrl":96,"categories":97,"keywords":98,"publishedAt":39},"01M71CFY9ATD0BAXV6B14HFG7C","yuri-shura","6-perspective adversarial review for high-stakes turns (architecture decisions, refactor planning, deployment review) — fans out architect, adversary (7-vector attack), maintainer, ops, product, and security perspectives in parallel, then consolidates. Use when user says 'review this decision', '\u002Fshura', 'adversarial review', 'what could go wrong', 'architecture review', or 'deployment review'.","https:\u002F\u002Fgithub.com\u002Fnexuslinkproductions\u002Fyuri-os\u002Fblob\u002Fmain\u002Fskills\u002Fyuri-shura\u002FSKILL.md",[],[99,100,80,101,102,20,103,104,105,106,107,85,108,87,109,110,111,112,113,114],"yuri shura","parallel","architecture review","planning","deployment","vector","strategic review","decision","strategic","ops","workflow","decisions","architecture","review","perspectives","adversarial",{"skillNo":116,"name":117,"nameZh":6,"description":118,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":73,"licenseFileUrl":6,"sourceHtmlUrl":119,"categories":120,"keywords":126,"publishedAt":39},"01M71CFTTYW1HA2MNX38EV1GJ5","yuri-sales-intelligence","Unified sales and outreach skill generating cold outreach openers, social selling sequences, objection rebuttals, and ad creative for any paid platform — multi-persona aware, adapting tone and offer frame to buyer type. Use when user says 'write a cold email', 'outreach sequence', 'objection handling', 'ad copy', or 'sales pitch'.","https:\u002F\u002Fgithub.com\u002Fnexuslinkproductions\u002Fyuri-os\u002Fblob\u002Fmain\u002Fskills\u002Fyuri-sales-intelligence\u002FSKILL.md",[121],{"categoryNo":122,"categoryName":123,"taxonomyType":124,"taxonomyTypeDesc":125},"01JBSEEDCAT000000000000005","邮件与沟通","SCENARIO","使用场景",[127,128,129,130,131,132,133,134,135,87,136,137,138,139,140,141,142,20,143,144],"intelligence","sales intelligence","yuri sales intelligence","sales","cold","paid","social","persona","pitch","cold email","ad creative","write","sequences","sequence","platform","email","cold outreach","frame",{"skillNo":146,"name":147,"nameZh":6,"description":148,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":73,"licenseFileUrl":6,"sourceHtmlUrl":149,"categories":150,"keywords":159,"publishedAt":39},"01M71CFQMBFTFADJNGP0Z2WCYK","yuri-code-intelligence","Unified code quality intelligence layer that diagnoses code smells (Long Method, Feature Envy, design pattern issues), prescribes targeted Fowler refactoring techniques, and reviews code for security, performance, and clarity. Use when user says 'review this code', 'refactor this', 'what's wrong with this method', 'code smells', or 'clean this up'.","https:\u002F\u002Fgithub.com\u002Fnexuslinkproductions\u002Fyuri-os\u002Fblob\u002Fmain\u002Fskills\u002Fyuri-code-intelligence\u002FSKILL.md",[151,154],{"categoryNo":152,"categoryName":153,"taxonomyType":124,"taxonomyTypeDesc":125},"01JBSEEDCAT000000000000007","代码审查",{"categoryNo":155,"categoryName":156,"taxonomyType":157,"taxonomyTypeDesc":158},"01JBSEEDCAT000000000000030","开发工程师","PROFESSION","适用职业",[160,89,161,127,80,162,163,164,20,165,166,167,168,169,170,171,172,173,85,87],"yuri code intelligence","code intelligence","reviews","code quality","feature","performance","code review","long","up","issues","clean","techniques","improve","design",{"skillNo":175,"name":176,"nameZh":6,"description":177,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":73,"licenseFileUrl":6,"sourceHtmlUrl":178,"categories":179,"keywords":180,"publishedAt":39},"01M71CFP32RT6GD3GKNHCJP8VP","yuri-adw","Invoke when user asks to run the ADW loop \u002F agentic engineering loop \u002F software factory workflow.","https:\u002F\u002Fgithub.com\u002Fnexuslinkproductions\u002Fyuri-os\u002Fblob\u002Fmain\u002Fskills\u002Fyuri-adw\u002FSKILL.md",[],[181,182,183,184,185,186,187,188,189,87,190,109,191,192],"yuri adw","run","engineering loop","software factory","software","agentic engineering","factory","loop","invoke","engineering","agentic","user",{"skillNo":194,"name":195,"nameZh":6,"description":196,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":73,"licenseFileUrl":6,"sourceHtmlUrl":197,"categories":198,"keywords":211,"publishedAt":39},"01M71CFK4VPEKY6A73237P7RSN","writing-skills","Use when creating new skills, editing existing skills, or verifying skills work before deployment","https:\u002F\u002Fgithub.com\u002Fnexuslinkproductions\u002Fyuri-os\u002Fblob\u002Fmain\u002Fskills\u002Fwriting-skills\u002FSKILL.md",[199,202,205,208],{"categoryNo":200,"categoryName":201,"taxonomyType":124,"taxonomyTypeDesc":125},"01JBSEEDCAT000000000000008","测试与质量",{"categoryNo":203,"categoryName":204,"taxonomyType":124,"taxonomyTypeDesc":125},"01JBSEEDCAT000000000000018","写作与文案",{"categoryNo":206,"categoryName":207,"taxonomyType":124,"taxonomyTypeDesc":125},"01JBSEEDCAT000000000000023","Skill与智能体开发",{"categoryNo":209,"categoryName":210,"taxonomyType":157,"taxonomyTypeDesc":158},"01JBSEEDCAT000000000000036","内容创作者",[212,213,214,87,109,215,80,216,103,85,217],"writing","writing skills","new","work","editing","Existing"]