129 lines
8.4 KiB
Markdown
129 lines
8.4 KiB
Markdown
# Cascades Tucson — Spoofed Email Hunt
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**Date:** 2026-04-21
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**Tenant:** Cascades of Tucson (cascadestucson.com, `207fa277-e9d8-4eb7-ada1-1064d2221498`)
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**Subject:** Tenant-wide email spoofing posture (inbound + domain authentication)
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**Tool:** Remediation-tool skill (public-DNS only — see Gaps)
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**Scope:** READ-ONLY
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**Analyst:** Howard Enos (ACG-Tech03L)
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## Summary
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- **Public domain-auth posture is largely solid.** SPF is strict (`-all`), DKIM publishes both M365 selectors, DMARC is at `p=quarantine; pct=100`.
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- **One real finding:** DMARC aggregate + forensic reports route to `info@cascadestucson.com` — an internal mailbox. No third-party DMARC aggregator is parsing failures. We have zero visibility into who is trying to spoof this domain.
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- **Lookalike domain landscape is clean** for common variants (no A records on `cascadetuscon.com`, `cascadestuscon.com`, `cascadestucson.co/.net/.org`, `cascades-tucson.com`). Worth a deeper scan if concern warrants.
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- **Inbound-side hunt is BLOCKED** — Cascades is only consented to the deprecated app (`fabb3421`), and the new tiered-app secrets are missing from Howard's local vault. Cannot run message trace, anti-phishing policy review, transport-rule audit, or quarantine review without one of: (a) syncing the new app secrets from Mike's vault, or (b) consenting Security Investigator in Cascades.
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- **SPF includes one non-Microsoft IP** (`72.194.62.5`) — identified as `ix.azcomputerguru.com` (our own iXsystems host). Authorized, not a finding.
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## Target details
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| Field | Value |
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|---|---|
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| Domain | cascadestucson.com |
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| Tenant ID | 207fa277-e9d8-4eb7-ada1-1064d2221498 |
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| M365 base domain | NETORGFT4257522.onmicrosoft.com |
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| MX | cascadestucson-com.mail.protection.outlook.com (M365 only) |
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| App suite status | Old app only (`fabb3421`); tiered suite not consented |
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## Per-check findings
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### 1. SPF
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```
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v=spf1 ip4:72.194.62.5 include:spf.protection.outlook.com -all
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```
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- **Mechanism:** strict `-all` (hard fail) — correct posture.
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- **Authorized senders:** M365 (`spf.protection.outlook.com`) + one explicit IP `72.194.62.5`.
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- **72.194.62.5 identification:** rDNS `ix.azcomputerguru.com`, ARIN block `NETBLK-PH-CBS-72-194-48-0` (Cox Business). This is ACG's own ix-server — presumably used for on-prem scan-to-email or a mail relay for Cascades. Not a finding.
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- **No third-party SPF includes** (no MailChimp, Constant Contact, HubSpot, etc.). Clean.
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### 2. DKIM
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- `selector1._domainkey.cascadestucson.com` -> `selector1-cascadestucson-com._domainkey.NETORGFT4257522.onmicrosoft.com` (M365 standard).
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- `selector2._domainkey.cascadestucson.com` -> `selector2-cascadestucson-com._domainkey.NETORGFT4257522.onmicrosoft.com` (M365 standard).
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- **Both DKIM selectors are published.** Can't confirm Exchange is actually signing without Exchange access (`Get-DkimSigningConfig` — blocked, see Gaps). Publish state is a prerequisite but not proof of enforcement.
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### 3. DMARC
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```
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v=DMARC1; p=quarantine; pct=100; rua=mailto:info@cascadestucson.com; ruf=mailto:info@cascadestucson.com; ri=86400; fo=1;
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```
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| Tag | Value | Assessment |
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|---|---|---|
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| `p` | quarantine | Acceptable — quarantines failures. `reject` is stronger but higher-risk to deploy without monitoring. |
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| `pct` | 100 | Full enforcement — good. |
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| `rua` | info@cascadestucson.com | **FINDING — aggregate reports go to an internal mailbox. No one is parsing them.** |
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| `ruf` | info@cascadestucson.com | **FINDING — forensic reports (full failing messages) go to an internal mailbox. Privacy/noise risk + no analysis.** |
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| `ri` | 86400 (24h) | Standard reporting interval. |
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| `fo` | 1 | Forensic generated on ANY SPF/DKIM fail — aggressive, OK for investigation. |
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| `sp` | (unset) | Subdomain policy inherits from `p` — acceptable. |
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| `adkim`/`aspf` | (unset, relaxed default) | Acceptable. |
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**Subdomain DMARC:** no subdomain-specific record observed at `_dmarc.sub.cascadestucson.com`, so subdomain behavior falls back to the org policy — fine.
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### 4. Lookalike-domain quick scan
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No A records for any of these obvious variants:
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| Candidate | Status |
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|---|---|
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| cascadetuscon.com | no A record |
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| cascadestuscon.com | no A record |
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| cascadestucson.co | no A record |
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| cascadestucson.net | no A record |
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| cascadestucson.org | no A record |
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| cascades-tucson.com | no A record |
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Not exhaustive — a proper lookalike hunt would also check registrations without A records (squatters parking domains), homoglyphs (Cyrillic "а", "ᴄ"), and newly-registered variants. Not done in this pass.
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### 5. Inbound spoofing attempts — BLOCKED (see Gaps)
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Needed but not collected (require Exchange Online access):
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- **Message trace** for last 7–30 days filtering on `SenderAddress` matching internal-spoofing patterns (same domain, but from external IP).
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- **Anti-phishing policy review** — spoof intelligence enabled? Impersonation protection configured for executives (Meredith, etc.)?
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- **Quarantine review** — currently-quarantined messages tagged as spoofing.
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- **Transport rules** — any rule bypassing SCL/anti-phish for specific senders (a known attacker persistence technique).
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- **Accepted domains** — verify no unauthorized domains added as internal.
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- **Connection filter policy** — any IPs improperly on the Allow list.
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- **Defender for O365 alerts** (if licensed) — MDO spoof detections.
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## Suspicious items (from public data)
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- **DMARC reports are a blind spot.** `rua=mailto:info@cascadestucson.com` means aggregate reports from every receiver on the internet are flowing into the same mailbox Cascades uses for external-facing communication — nobody is aggregating them. If someone is actively spoofing cascadestucson.com at scale, we'd have no idea unless a user happened to read those XML attachments. **High-leverage fix** — point `rua` (and optionally `ruf`) at a DMARC aggregator (dmarcian, EasyDMARC, Valimail — all have free tiers for small-volume domains).
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## Gaps — checks not completed
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**All inbound / Exchange-side checks are blocked by tooling state:**
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1. **Cascades is not onboarded to the new app suite.** Per `references/tenants.md` (row `cascadestucson.com`): "Old app only; IdentityRiskyUser not consented". Tiered Security Investigator never got consent in this tenant.
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2. **Even if consented, Howard's vault is missing the new-suite client secrets.** Expected at `D:/vault/msp-tools/computerguru-security-investigator.sops.yaml` — file does not exist. These secrets live in Mike's vault (DESKTOP-0O8A1RL) and have not been committed/synced to the shared vault repo.
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3. **The old app (`fabb3421`) IS consented in Cascades and its secret IS present** at `D:/vault/msp-tools/claude-msp-access-graph-api.sops.yaml`. However `get-token.sh` has no tier mapping for the old app (intentional — it's deprecated). Using it would require a one-off script. The remediation-tool design explicitly pushes toward migrating off it.
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**Recommended unblock (pick one):**
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- **Option A (preferred):** Mike commits/pushes new-suite SOPS files from his vault to the shared vault repo, then Howard pulls. Enables running this hunt on ANY tenant from Howard's box going forward.
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- **Option B:** Consent Security Investigator in Cascades now (send Global Admin the consent URL below), then Option A is still needed to acquire a token on Howard's box.
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Security Investigator consent URL for Cascades:
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```
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https://login.microsoftonline.com/207fa277-e9d8-4eb7-ada1-1064d2221498/adminconsent?client_id=bfbc12a4-f0dd-4e12-b06d-997e7271e10c&redirect_uri=https://azcomputerguru.com&prompt=consent
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```
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## Next actions
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1. **Decision on unblock path** — Howard to coordinate with Mike on vault sync (Option A above). Blocks full inbound hunt.
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2. **DMARC reporting fix** — update `_dmarc.cascadestucson.com` TXT record to route `rua` (and `ruf`) at a DMARC aggregator. Pending client approval. Requires DNS access at cascadestucson.com registrar. Est. 15 min.
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3. **Deeper lookalike-domain scan** — out of scope for this pass; consider running dnstwist or a registrar monitoring service if spoofing pressure is elevated.
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4. **Once unblocked, re-run with:** message trace last 30d for `cascadestucson.com` spoofing indicators, anti-phishing policy inventory, transport rules, quarantine review, Defender alerts (if MDO licensed).
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## Remediation actions
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None taken. This pass was read-only / public-DNS only.
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## Data artifacts
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No raw JSON produced (tokens were not acquired). DNS lookups are reproducible from the commands in the Per-check findings section.
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