OneNote .one attachment → embedded payload → C2
OneNote .one file with a friendly 'Double-click to view' overlay hides an embedded HTA / VBS / EXE. Effective initial access vector after Microsoft blocked internet macros in 2022.
§ Context
Assumed environment: target users routinely receive .one attachments (legit OneNote usage). Endpoints don't disable embedded files in OneNote (CVE-2024-30050 / GP mitigation).
§ Steps
- 01Persistence + reconPersistenceT1547— Boot or Logon Autostart Execution
- 02Stager downloads beaconCommand and ControlT1071— Application Layer Protocol
- 03Email with .one attachmentInitial AccessT1566— Phishing
- 04Victim opens OneNoteExecutionT1204— User Execution
- 05Clicks the deceptive 'View document' buttonExecutionPAY-ONENOTE— Malicious OneNote Attachment
- 06Embedded HTA / VBS runsExecutionPAY-HTA-VBS— HTA / VBS / WSF Execution
§ References
§ Frequently asked
- What is the "OneNote .one attachment → embedded payload → C2" attack path?
- OneNote .one file with a friendly 'Double-click to view' overlay hides an embedded HTA / VBS / EXE. Effective initial access vector after Microsoft blocked internet macros in 2022. It chains 6 steps drawn from real-world offensive-security techniques.
- What starting position does this attack require?
- The first step is Persistence + recon (T1547) — a persistence primitive. Assumed environment: target users routinely receive .
- What is the final impact of this kill-chain?
- The final step lands on Embedded HTA / VBS runs (PAY-HTA-VBS), which falls under Execution. From here, an operator typically pivots into post-exploitation or maintains persistence.
- How can defenders detect or prevent this attack?
- Detection and prevention vary per step. Refer to each linked MITRE ATT&CK entry under "References" — every technique on that page lists defensive controls, detection telemetry, and known threat-actor usage.
§ Related dossiers
- Shared techniques3
ISO container → LNK → stage from CDN → C2
Email attaches an ISO. Windows mounts it as a drive, bypassing Mark-of-the-Web. LNK inside runs a hidden binary that pulls the real stager from a CDN — Defender often misses the chain.
- Shared techniques2
Malicious MCP server → silent supply chain for agent tools
User installs an MCP server marketed as a useful integration. Every subsequent agent session has the rogue server in scope — its tools log prompts, exfil files, or inject responses to bias the agent.
- Shared techniques2
V8 type-confusion 1-day → renderer RCE
Public V8 type-confusion turned into a renderer pop. JS triggers JIT into mis-compiling a polymorphic site, addrof/fakeobj primitives, shellcode in a WASM RWX page.
- Shared techniques2
Header smuggling → gateway sees vendor, mailbox sees attacker
Crafted RFC-edge headers cause SPF/DMARC to validate against one From while Outlook renders the other — slips past Microsoft Defender / Proofpoint and lands as a 'verified' message.
- Shared techniques2
Compromised vendor mailbox → reply-chain phishing → client compromise
Take over a vendor / partner mailbox via AITM phishing. Reply to an existing thread with a malicious link — trust transferred from the genuine prior conversation defeats most user training.
- Shared techniques2
Rowhammer → bit flip → in-browser sandbox escape
JavaScript hammers adjacent DRAM rows for tens of seconds; an unlucky-for-defender bit flip in a page-table entry hands the attacker a write primitive into another mapping. RIDL-class chain to native code.