Soc2 evidence collection

SOC 2 Evidence Collection

Overview

This skill implements automated and semi-automated evidence collection for SOC 2 Type I/II examinations. Evidence must be complete, dated, tamper-evident, and mapped to TSC control IDs. The agent uses MCP tools where available:

• Playwright MCP: screenshots, DOM/state captures for web admin consoles
• Postgres MCP: query exports for access lists, change tickets, control status
• Slack MCP: export approval messages (redacted) for change management evidence
• Shell/API exports: IAM policies, Terraform state metadata, cloud config snapshots

Every artifact receives a SHA-256 hash and entry in an evidence manifest suitable for auditor import.

When to Use

Use this skill when:

• Building an audit evidence binder for SOC 2 Type I or Type II
• Responding to auditor evidence requests (ERDs, sample periods)
• Populating GRC platform evidence slots (Vanta, Drata, Secureframe alternatives)
• Packaging quarterly control testing results
• Collecting point-in-time and period-of-time samples (Type II requires continuous samples)
• Documenting agent/MCP compliance after running other skills (PCI, HIPAA)

Do not use this skill when:

• Defining which TSC controls apply (use soc2-trust-services-criteria)
• Real-time drift detection (use soc2-ccm-continuous-monitoring)
• Replacing auditor judgment on sample adequacy

Core Process

Execute steps in order.

Step 1: Evidence request intake

1. Obtain auditor evidence request list or map from TSC control matrix.
2. For each request, record:
   • Control ID (e.g., CC6.1, CC7.2)
   • Evidence type (screenshot, config export, log sample, policy PDF)
   • Sample period (for Type II: e.g., Q1–Q4 2025)
   • Population and sample size (auditor may specify)
3. Artifact: evidence-request-register-{id}.csv.

Step 2: Collection plan and tool mapping

Evidence type	Primary collection method	MCP/tool
IAM user list + MFA status	Cloud API or IdP export	Shell, Postgres
Admin console screenshot	Authenticated browser capture	Playwright MCP
Firewall/security group rules	Cloud API JSON export	Shell
Change tickets	ITSM export	Postgres, API
Log sample (auth failures)	SIEM query export	Postgres, API
Policy documents	Document store hash	File read
Agent skill validation	Git commit + CI run	Shell
MCP access logs	Log aggregator export	Postgres

Identify blocking gaps (missing MCP credentials, read-only access)—document before collection.

Step 3: Automated collection execution

For each evidence item:

1. Collect using prescribed tool—do not manually recreate data that can be exported programmatically.
2. Redact ePHI/PII/secrets from evidence unless auditor specifically requires raw sample under NDA.
3. Timestamp collection in UTC; record collector identity (human or agent run ID).
4. Hash raw artifact: sha256sum equivalent; store in manifest.
5. Name files predictably: {control-id}_{evidence-type}_{date}.{ext}.

Playwright MCP screenshot protocol

1. Authenticate to target console via approved test account (not production admin unless authorized).
2. Navigate to exact page showing control (e.g., MFA enforcement policy).
3. Capture full-page screenshot including URL bar and timestamp overlay if available.
4. Save as PNG with manifest entry.

Postgres MCP export protocol

1. Run read-only queries against compliance/evidence schema only.
2. Export CSV/JSON; limit rows to sample size.
3. Verify query logged in audit trail.

Step 4: Period-of-time sampling (Type II)

1. For each recurring control (access reviews, vulnerability scans, backup tests):
   • Collect one sample per required interval in examination period (e.g., quarterly access review × 4).
2. Verify samples are evenly distributed—not all collected last week before audit.
3. Flag missing intervals as FAIL with remediation note.

Step 5: Integrity and chain of custody

1. Generate evidence-manifest-{id}.json:

   {
     "artifact_id": "EV-2025-001",
     "control_id": "CC6.1",
     "filename": "CC6.1_mfa-enforcement_2025-06-13.png",
     "sha256": "...",
     "collected_at_utc": "...",
     "collector": "...",
     "source_system": "playwright-mcp"
   }
   

2. Sign manifest or store in append-only evidence bucket (WORM, S3 Object Lock).
3. Package as evidence-bundle-{id}.tar.gz with manifest at root.

Step 6: Control cross-reference validation

1. Map every manifest entry to TSC control ID—no orphan artifacts.
2. Map every auditor request to ≥1 artifact—or document exception with compensating evidence.
3. Cross-check dates fall within sample period.

Step 7: Auditor delivery package

1. Produce:
   • Evidence bundle (encrypted at rest for transit)
   • Index spreadsheet: Control ID → filename → hash → description
   • Collection methodology note (tools, redaction approach, limitations)
2. Obtain internal reviewer sign-off before external delivery.

Common Rationalizations

Excuse the agent might generate	Required rebuttal
"A verbal confirmation is enough for CC8 change approval."	SOC 2 requires verifiable evidence—ticket export or signed approval message with timestamp.
"One screenshot at audit time covers the whole Type II period."	Type II requires period-of-time samples across the examination window—not point-in-time only.
"We can recreate logs from memory for the sample."	Recreated logs are not auditable—export from authoritative SIEM/system.
"Hashes are overkill for screenshots."	Integrity hashes prove evidence unchanged since collection—auditors expect them.
"Redaction removes too much; send raw PHI to auditor email."	Use secure auditor portal with minimum necessary redaction—never unencrypted email.
"Missing Q2 access review—we'll note it later."	Missing intervals are findings—document now with remediation plan.

Red Flags

• Evidence collected entirely in final audit week for 12-month Type II period
• Screenshots without URL/context proving system and date
• Config exports contain live secrets or API keys unredacted
• Manifest missing hashes or UTC timestamps
• Orphan artifacts not mapped to control IDs
• Playwright captures using unauthorized production credentials
• Evidence bundle transmitted unencrypted via email or Slack

Verification

• Evidence request register complete with control IDs and sample periods
• Collection plan maps each request to tool/method
• All artifacts collected with UTC timestamps and collector identity
• SHA-256 recorded for every artifact in manifest
• Type II recurring controls have samples for each required interval
• ePHI/secrets redacted per minimum necessary policy
• Playwright screenshots include authenticating context (URL, policy visible)
• No orphan artifacts or unfulfilled auditor requests without documented exception
• Evidence bundle packaged with immutable storage or Object Lock
• Internal reviewer sign-off recorded before auditor delivery