Malicious Office (OLE) / .DOC — malware analysis report

Static analysis result for SHA-256 c37b6635cf769abd…

MALICIOUS

Office (OLE) / .DOC

3.0 KB First seen: 2026-03-07
MD5: ffd4569463938aa97b02a323d0c1c21b SHA-1: 5b2d8a64d436fde66a933bd4abde4225a77d26bc SHA-256: c37b6635cf769abdcd72f70137c2dcb8321afc185358a7323f4db4efda791d33
80 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File Execution: Malicious File T1059.003 Command and Scripting Interpreter: Windows Command Shell

The critical heuristic firing indicates the file exploits CVE-2017-11882, a known vulnerability in Microsoft Equation Editor. The exploit uses a nibble-shifted technique and a stager that executes 'rundll32'. The OLE parsing heuristic suggests the file may be truncated or deliberately malformed to evade detection. No document body or scripts were extracted, but the exploit itself is sufficient to classify the attack pattern.

Heuristics 2

  • Nibble-shifted Equation Editor exploit — CVE-2017-11882 critical CVE likely CVE_2017_11882
    The file has a CFB (OLE2) header but no readable streams, and dropping one leading 4-bit nibble re-aligns the content to expose the Microsoft Equation 3.0 CLSID together with an execution stager / the EQNEDT32.EXE return gadget. Whole-file nibble shifting is a deliberate evasion that defeats olefile parsing and every byte-aligned signature while Office still loads the object — an unambiguous CVE-2017-11882/0802 dropper.
  • CFB header with no readable streams medium OLE_PARSE_EMPTY_STREAMS
    The file begins with a valid OLE2/CFB header but exposes no directory streams. A non-empty compound document with an unreadable directory is anomalous — it is seen with truncated/corrupt files and, more importantly, with content deliberately shifted off byte boundaries to defeat parsers while the host application still recovers the object.