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

Static analysis result for SHA-256 6fd21392a247d3f5…

MALICIOUS

Office (OLE) / .DOCX

901.0 KB Created: 2021-07-06 12:06:00 Authoring application: Microsoft Office Word
MD5: cd7e2ac74f739efc610a4f0849d61825 SHA-1: e13d9c0482baa3b7712119de56a40b1dedbb9f28 SHA-256: 6fd21392a247d3f5cc83de50e1006010c438b609158ac5e7b6408627fdd4aa0b
642 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is a malicious Microsoft Word document that exploits CVE-2007-3899, a memory corruption vulnerability, to gain execution. It contains a VBA macro named 'Document_Open' which is designed to execute automatically. This macro attempts to write a file named 'niberius.dll' to the user's templates path and then attempts to execute it via a Run key entry. The macro also contains logic to potentially download and execute a second-stage payload, indicated by the use of CreateProcess and ShellExecute APIs, and the presence of an embedded PE executable.

Heuristics 16

  • CVE-2007-3899 — Microsoft Word malformed string memory corruption critical CVE likely CVE_2007_3899
    Word OLE document has the MS07-060 malformed-string exploit shape: a Word 97-family FIB points to a malformed DOP/string-table region with an abnormal INT_MAX run, inflated text counters, and exploit payload or Mdropper.Z campaign evidence.
  • Office EPRINT stream contains EMF object high CVE related OLE_EPRINT_EMF_OBJECT
    OLE ObjectPool contains an EPRINT stream with EMF data. This is rare in normal documents and is CVE-2007-3893/MS07-046-family evidence when paired with Office exploit payload anomalies, but the malformed EMF record is not proven by this rule alone.
  • OLE with Ole10Native — possible CVE-2026-21514 exploitation high CVE likely CVE_2026_21514
    Document contains a Word OLE object with Ole10Native plus executable, PE, or risky remote-link indicators. CVE-2026-21514 exploits OLE metadata validation; this stronger structure is treated as likely exploitation.
  • Embedded PE executable critical OLE_EMBEDDED_EXE
    MZ/PE header found inside document — possible embedded executable
  • ClamAV: Win.Trojan.Generic-9876346-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Generic-9876346-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Reference to CreateProcess API high SC_STR_CREATEPROCESS
    Reference to CreateProcess API
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • Reference to LoadLibrary API high SC_STR_LOADLIBRARY
    Reference to LoadLibrary API
  • Reference to GetProcAddress API high SC_STR_GETPROCADDRESS
    Reference to GetProcAddress API
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • Ole10Native package carries executable/script file type high OFFICE_PACKAGE_RISKY_FILE
    OLE Package displayName or fullPath ends in an executable or script-capable extension. Even without UI extension spoofing, embedding a runnable payload inside an Office document is a high-risk delivery pattern.
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Reference to VirtualProtect API medium SC_STR_VIRTUALPROTECT
    Reference to VirtualProtect API
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/drawingml/2006/main

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
e71d307f9d10461ac01ffd83b84bd3b183b6ceb16528afc94404f1086c39a1ab		 vba-macro oletools.olevba.extract_macros (decoded VBA source) 2990 bytes
embedded_office_0008ec71.exe
cdb5737280a67a2a88f5b7e6841e8acfdbaa29a0e44d1063b2b63fdf5b2e4a41		 embedded-pe Office MZ+PE at offset 0x8EC71 337807 bytes
Detection
ClamAV: Win.Trojan.Injectorx-9876306-0
Obfuscation or payload: unlikely
ole10native_00.bin
554b8fc37d3a74a10f07f55f93ebc433b8d1a67d9f98e4ed0a462025a1885cf3		 ole-package OLE Ole10Native stream: ObjectPool/_1687053204/Ole10Native 298805 bytes
Detection
ClamAV: Win.Trojan.Generic-9876346-0
Obfuscation or payload: unlikely

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