Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c86648f2699bfc41…

MALICIOUS

Office (OLE)

901.0 KB Created: 2021-07-06 12:10:00 Authoring application: Microsoft Office Word
MD5: c20dc6f1340f89a35f43c110ee904124 SHA-1: f06b6bca9090f63e43151114b482e863cd5f5f2e SHA-256: c86648f2699bfc4108c39b413374976eb7d1d1dbf8fbf275a9aa25c11ce836c4
642 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1105 Ingress Tool Transfer

The sample is a malicious Microsoft Word document exploiting CVE-2007-3899, a memory corruption vulnerability. It contains a VBA macro named Document_Open which is designed to execute a second-stage payload. The macro attempts to write and execute a DLL file named 'niberius.dll' and also attempts to establish persistence by writing to the registry key HKCU\Software\Microsoft\Windows\CurrentVersion\Run\IAccessible2Proxy. An embedded PE executable and an OLE package were also detected.

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
d23ef93f225c61e8854957fce7e631c2ebffe620e2c4bb922010ce524af72354
embedded-pe Office MZ+PE at offset 0x8EC71 337807 bytes
Detection
ClamAV: Win.Trojan.Injectorx-9876306-0
Obfuscation or payload: unlikely
ole10native_00.bin
0dfffde15641caea292c6cc7a606b5e0500bf18ffc72ffc2871a1341a138e8b8
ole-package OLE Ole10Native stream: ObjectPool/_1687053743/Ole10Native 298805 bytes
Detection
ClamAV: Win.Trojan.Generic-9876346-0
Obfuscation or payload: unlikely