Techniques › T1027.016 › AN0913
AN0913 Analytic 0913
Windows · attack.mitre.org · ATT&CK Enterprise v19.2
<p>Detects the presence of executables with high NOP padding, unusually large binary size for their function, and follow-on execution or memory injection from such files, especially when originating from temp or user-space paths.</p>
- Detects
- T1027.016 Junk Code Insertion
- Part of
- DET0322 Detection Strategy for Junk Code Obfuscation with Suspicious Execution Patterns
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=10 | DC0035 Process Access |
| WinEventLog:Sysmon | EventCode=1 | DC0032 Process Creation |
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 |
|---|---|
NOPThreshold | High proportion of 0x90 opcodes indicating junk code – tune to suppress noise from some packing tools |
ExecutableSizeThreshold | Size range for abnormally large binaries relative to their runtime behavior |
TimeWindow | Window between file creation and execution – short intervals may indicate staged payload execution |