Techniques › T1027.006 › AN0872
AN0872 Analytic 0872
Windows · attack.mitre.org · ATT&CK Enterprise v19.2
<p>Detection of browser-based or email client-driven file creation (often from temp directories) following navigation to or execution of HTML files containing JavaScript Blob APIs or base64 Data URLs, with follow-on execution of the dropped payload. Leveraging Sysmon EventID 15 to inspect Zone.Identifier ADS for HostUrl/ReferrerUrl indicators (e.g., HostUrl=about:internet). Optional: absence of a large HTTP download record for the same URL/client in proxy logs (suggests local assembly)</p>
- Detects
- T1027.006 HTML Smuggling
- Part of
- DET0313 Detection Strategy for HTML Smuggling via JavaScript Blob + Dynamic File Drop
Log sources and channels
Exactly as MITRE states them in x_mitre_log_source_references. Where a channel is vague, it is vague in the source; kevmap does not tidy it.
| Log source | Channel | Data component |
|---|---|---|
| WinEventLog:Sysmon | EventCode=11 | DC0039 File Creation |
| WinEventLog:Sysmon | EventCode=1 | DC0032 Process Creation |
| EDR:detection | App reputation telemetry | DC0059 File Metadata |
| WinEventLog:Sysmon | EventCode=15 | DC0059 File Metadata |
| Network Traffic | None | DC0085 Network Traffic Content |
Mutable elements
Parameters MITRE marks as environment-specific. These are the knobs you are expected to tune; they are why an analytic is not a rule.
| Field | Description |
|---|---|
TimeWindow | Time range between HTML file open and file drop + execution (e.g., 1–10 minutes) |
DroppedFileExtensionWatchlist | Tunable list of file extensions of interest (e.g., .js, .hta, .exe) |
ParentProcessName | Expected processes that may drop files (e.g., browser, Outlook); tune for normal behavior |