Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 d2a101841431e6bb…

MALICIOUS

Office (OOXML)

42.1 KB Created: 2021-06-22 12:43:05 UTC Authoring application: Microsoft Excel 16.0300
MD5: ef48bc18b59d5aa0bd6610bb19ab5814 SHA-1: 418439da68b708f85969c341ff9aee2f4a03a3ee SHA-256: d2a101841431e6bbee9c86182ff6ea49ff59f89b25b573decdcce302800db04f
260 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1218.011 System Binary Proxy Execution: Rundll32 T1059.003 Windows Command Shell

The OOXML document contains a Workbook_Open macro that references PowerShell and cmd.exe. The critical heuristic OLE_VBA_WMI_PROCESS_CREATE indicates that the VBA code uses WMI to launch a process. This suggests the macro is designed to execute a second-stage payload, likely PowerShell, to further compromise the system. The VBA code also contains Base64 decoding logic, which is commonly used to obfuscate malicious payloads.

Heuristics 6

  • PowerShell reference in VBA critical OLE_VBA_PS
    PowerShell reference in VBA
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
2abc92d166b7e78811b60ed42bf1558d3c98a129957adceaa6830c630543094e		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 36038 bytes
vbaProject_00.bin
f61c38a5e59731b7e90481e33c4c2b0a3993899fcb8b9aa7e995f4417d52b9ec		 vba-project OOXML VBA project: xl/vbaProject.bin 11776 bytes

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