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

Static analysis result for SHA-256 c1b9683125a43d69…

MALICIOUS

Office (OLE) / .D

64.0 KB Created: 2000-03-07 07:09:00 Authoring application: Microsoft Word 8.0
MD5: 43ac8694b330f589295e3b0889ea618c SHA-1: 04fee22dd686e80ab913770627f6c47c588f085d SHA-256: c1b9683125a43d695314a633e79762ff055941e1d656a20471ad4d6d26563a65
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1027 Obfuscated Files or Information

The file is an OLE document containing VBA macros, specifically triggering AutoOpen and Document_Open heuristics, indicating an attempt to automatically execute code upon opening. The 'EXTRACTED_FILE_STATIC_TRIAGE' heuristic flagged VBA Chr string obfuscation within the 'macros.bas' file, suggesting the macros are intentionally obscured. The large slack space in the OLE structure is also a suspicious artifact. The primary intent appears to be the execution of obfuscated VBA code, likely to download and run a secondary payload.

Heuristics 5

  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 65,536 bytes but its declared streams total only 30,283 bytes — 35,253 bytes (54%) live in unallocated sector slack. This is the canonical hiding place for pre-macro-era Office exploit payloads (XOR-encoded shellcode reached via a parser pointer-corruption bug in the document structure).
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
c9e6ec471703de035a81de8542e5bb8dae820ab270e604e9196681d9b48b867d
vba-macro oletools.olevba.extract_macros (decoded VBA source) 16660 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 14 Chr/ChrW string-construction calls.