Phone Number Spoofing: Official Phone Number Spoofing
Plan and execute authorized vishing (voice phishing) pretext calls to
Install / Use
npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill conducting-social-engineering-pretext-callInstalls into whichever agent you are using.
SKILL.md
Installable skill definition
Quality Score
Category
SecuritySupported Platforms
Our assessment of Phone Number Spoofing: Official Phone Number Spoofing
Phone Number Spoofing: Official Phone Number Spoofing scores 91/100 on our quality scale, 239th of 544 Security skills we index (top 44%).
Its SKILL.md is 8.0 KB long, well organised into 24 sections with 1 code example: a thorough specification that gives an agent plenty to work with.
With 33,340 GitHub stars, it is one of the more widely adopted skills in the catalogue.
Maintenance, license and trust
- The repository was last updated 25 days ago, so Phone Number Spoofing: Official Phone Number Spoofing is actively maintained.
- It is released under the Apache-2.0 license, a permissive license that allows use, modification and commercial use with attribution.
- Its trust signals score 100/100, with no cautions. These come from repository metadata, not a code audit — read the skill file before letting an agent act on it.
Safety scan
ReviewOur scan of the whole file found no instruction hijacking, hidden characters, credential access, data exfiltration or destructive commands. An AI review judged it risky (a second model did not confirm it as malicious): The skill instructs the agent to impersonate IT helpdesk, vendors, or executives and explicitly script requests for usernames, passwords, employee IDs, and badge numbers.
AI review: risky
- The skill instructs the agent to impersonate IT helpdesk, vendors, or executives and explicitly script requests for usernames, passwords, employee IDs, and badge numbers.
- It directs the agent to spoof caller IDs, gather OSINT on targets, and use pressure tactics/objection-handling scripts to bypass verification and extract credentials.
- Although it mentions authorization, as a skill file these are actionable instructions for deception and credential theft, and the safety framing itself is a red flag.
AI review by kimi-k2.7-code with a second opinion from glm-5.3 on 2026-09-26. Automated pattern scan on 2026-09-25. It catches known dangerous patterns, not every risk — read a skill before letting an agent act on it.
Phone Number Spoofing: Official Phone Number Spoofing compared with similar skills
All 4 of these similar skills score higher than Phone Number Spoofing: Official Phone Number Spoofing; compare them before choosing.
| Skill | Score | Stars | Updated | Format |
|---|---|---|---|---|
| Phone Number Spoofing: Official Phone Number Spoofing (this skill)by mukul975 | 91 | 33.3k | 25d ago | SKILL.md |
| LocalAIby mudler | 100 | 49.3k | today | MCP Server |
| algorithmic-artby anthropics | 100 | 177.9k | 3d ago | SKILL.md |
| pptxby anthropics | 100 | 177.9k | 3d ago | SKILL.md |
| designby nextlevelbuilder | 100 | 130.2k | 4d ago | SKILL.md |
Frequently asked questions
- How do I install Phone Number Spoofing: Official Phone Number Spoofing?
- Run
npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill "Phone Number Spoofing: Official Phone Number Spoofing". The install tabs above show the steps for each supported agent. - Which AI agents does Phone Number Spoofing: Official Phone Number Spoofing work with?
- It is written for Zed, as a SKILL.md file. Other agents that read the same format can often use it too.
- Is Phone Number Spoofing: Official Phone Number Spoofing safe to use?
- Our scan of the whole file found no instruction hijacking, hidden characters, credential access, data exfiltration or destructive commands. An AI review judged it risky (a second model did not confirm it as malicious): The skill instructs the agent to impersonate IT helpdesk, vendors, or executives and explicitly script requests for usernames, passwords, employee IDs, and badge numbers. It is Apache-2.0-licensed and scores 100/100 on trust signals. Skills are instructions an agent will follow, so read the file before installing it and do not approve commands you do not understand.
- Is Phone Number Spoofing: Official Phone Number Spoofing still maintained?
- The repository was last updated 25 days ago, so Phone Number Spoofing: Official Phone Number Spoofing is actively maintained.
Skill content
View source on GitHubname: conducting-social-engineering-pretext-call description: Plan and execute authorized vishing (voice phishing) pretext calls to assess employee susceptibility to social engineering and evaluate security awareness controls. domain: cybersecurity subdomain: red-teaming tags:
- social-engineering
- vishing
- pretext-call
- security-awareness
- red-team
- phishing
- human-risk version: '1.0' author: mahipal license: Apache-2.0 atlas_techniques:
- AML.T0088
- AML.T0052 nist_ai_rmf:
- GOVERN-6.2
- MAP-5.2 d3fend_techniques:
- File Metadata Consistency Validation
- Application Protocol Command Analysis
- Identifier Analysis
- Content Format Conversion
- Message Analysis nist_csf:
- ID.RA-01
- GV.OV-02
- DE.AE-07 mitre_attack:
- T1598.004
- T1566.004
- T1589
- T1591
- T1598
mitre_f3:
version: '1.1'
tactics:
- reconnaissance
- initial-access
- stealth techniques:
- id: T1598 name: Phishing for Information tactic: reconnaissance source: attack
- id: F1034 name: Interactive Voice Response Mapping tactic: reconnaissance source: f3
- id: F1029 name: Gather Customer Information tactic: reconnaissance source: f3
- id: F1032 name: Impersonate Official tactic: initial-access source: f3
- id: F1040 name: Phone Number Spoofing tactic: stealth source: f3
- id: F1040.002 name: 'Phone Number Spoofing: Official Phone Number Spoofing' tactic: stealth source: f3
Conducting Social Engineering Pretext Call
Overview
A pretext call (vishing) is a social engineering technique where an attacker impersonates a trusted authority figure over the phone to manipulate targets into divulging sensitive information, performing actions, or granting access. In red team engagements, pretext calls test the human element of security controls, measuring employee adherence to verification procedures and security awareness training effectiveness. MITRE ATT&CK maps this to T1566.004 (Phishing for Information: Voice) and T1598 (Phishing for Information).
When to Use
- When conducting security assessments that involve conducting social engineering pretext call
- When following incident response procedures for related security events
- When performing scheduled security testing or auditing activities
- When validating security controls through hands-on testing
Prerequisites
- Written authorization specifying social engineering scope and boundaries
- List of approved target employees (usually provided by client)
- OSINT research on targets and organization
- Spoofed caller ID capability (authorized for testing)
- Call recording equipment (with legal consent as required)
- Pretext scenarios approved by client
MITRE ATT&CK Mapping
| Technique ID | Name | Tactic | |---|---|---| | T1566.004 | Phishing: Voice | Initial Access | | T1598 | Phishing for Information | Reconnaissance | | T1598.003 | Phishing for Information: Spearphishing Voice | Reconnaissance | | T1589 | Gather Victim Identity Information | Reconnaissance | | T1591 | Gather Victim Org Information | Reconnaissance |
Phase 1: OSINT and Target Research
# LinkedIn employee enumeration
theHarvester -d targetcorp.com -b linkedin -l 200
# Company org chart and employee roles
# Review LinkedIn, corporate website "About Us" / "Team" pages
# Technology stack identification
# Check job postings for technology references (VPN vendor, email, helpdesk tool)
# Phone system identification
# Call main line, note IVR options, department names, extension patterns
Key intelligence to gather:
- Internal helpdesk phone number and procedures
- IT department names and staff
- VPN/remote access vendor (Cisco AnyConnect, Fortinet, Pulse Secure)
- Corporate email format (first.last, flast, etc.)
- Recent events (mergers, office moves, system upgrades)
- Employee names, titles, departments
Phase 2: Pretext Development
Common Pretext Scenarios
IT Helpdesk Impersonation (Most Effective):
"Hi, this is [name] from the IT Service Desk. We're migrating everyone to the new VPN client this week, and I see your account hasn't been updated yet. I need to verify your current credentials to ensure the migration goes smoothly. Can you confirm your username and current password?"
Vendor/Contractor:
"Hi, I'm [name] from [known vendor]. We're doing an emergency patch deployment for [product] and I need remote access to your system. Could you help me connect via TeamViewer?"
Executive Assistant (Authority):
"This is [name] calling on behalf of [CFO name]. [He/She] needs an urgent wire transfer processed for a deal that's closing today. I'll email you the details, but we need this done in the next hour."
Building/Facilities:
"Hi, this is [name] from facilities management. We're updating the badge access system this weekend. I need to confirm your employee ID and current badge number so your access isn't interrupted."
Pretext Checklist
- [ ] Is the pretext believable for this organization?
- [ ] Does it create appropriate urgency without being threatening?
- [ ] Does it align with OSINT findings (real dept names, real systems)?
- [ ] Does it have a plausible reason for requesting information?
- [ ] Is there a fallback if the target pushes back?
- [ ] Has the client approved this specific pretext?
Phase 3: Call Execution
Call Structure
- Introduction (10 seconds): State name, department, reason for calling
- Building rapport (30 seconds): Reference something real (recent event, shared context)
- Authority establishment (20 seconds): Reference manager name, ticket number, urgency
- Information request (30 seconds): Ask for the target information naturally
- Handling objections: If challenged, respond calmly with prepared answers
- Closing (10 seconds): Thank them, leave no suspicion
Objection Handling
| Objection | Response | |---|---| | "Can I call you back?" | "Of course, call the main helpdesk line and ask for [name]. But this needs to be done by EOD." | | "I need to verify this" | "Absolutely, I appreciate your diligence. You can check with [manager name]." | | "I was told never to give passwords" | "You're right, and normally we wouldn't ask. This is a special case because [reason]. I can have my manager call you." | | "What's your employee ID?" | Pivot: "It's [made-up ID]. Listen, I have 50 more people to call today. Can we just get this done?" | | "I'll email IT instead" | "Sure, but the system migration happens tonight. If it's not done by then..." |
Phase 4: Data Collection and Metrics
Track the following for each call:
| Metric | Description | |---|---| | Target Name | Employee called | | Department | Target's department | | Date/Time | When call was made | | Duration | Length of call | | Pretext Used | Which scenario | | Information Obtained | What was disclosed | | Credential Disclosed | Yes/No (and type) | | Verification Attempted | Did target try to verify caller? | | Reported to Security | Did target report the call? | | Social Engineering Score | 1-5 susceptibility rating |
Phase 5: Reporting
Success Metrics
| Metric | Target | Result | |---|---|---| | Credential Disclosure Rate | <10% | XX% | | Sensitive Info Disclosure Rate | <20% | XX% | | Verification Rate | >80% | XX% | | Security Reporting Rate | >50% | XX% |
Ethical and Legal Considerations
- Always obtain written authorization before conducting vishing tests
- Never use threatening language or create genuine fear
- Document consent and legal requirements for call recording
- Protect disclosed credentials - immediately report to client
- Debrief targets after the engagement if client approves
- Never publicly identify specific employees who failed
- Comply with telecommunications laws in your jurisdiction
References
- Verizon DBIR 2025: 74% of breaches involve human element
- MITRE ATT&CK T1598: https://attack.mitre.org/techniques/T1598/
- Social Engineering Penetration Testing by Gavin Watson (Syngress)
- The Art of Deception by Kevin Mitnick (Wiley)
- NIST SP 800-50: Building an Information Technology Security Awareness and Training Program
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Trust signals
From repository metadata: license, adoption, age and documentation. Not a code audit — see the Safety scan above for what the skill file itself contains.
