Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 bb94f2bae7d1f4b3…

MALICIOUS

Office (OOXML)

42.1 KB Created: 2021-06-22 12:43:05 UTC Authoring application: Microsoft Excel 16.0300
MD5: 0bf53f6e1202db38fc89934f6546e4be SHA-1: 4a97cf7b64287cd37ab73bc7115409217eeaeb3f SHA-256: bb94f2bae7d1f4b3473fef97f21c60f5b0c090e925f7d6a63790df3de7aaab65
260 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file is an Excel document containing a Workbook_Open VBA macro. This macro references cmd.exe and PowerShell, and uses WMI to launch processes. The presence of a Workbook_Open macro strongly suggests an attempt to execute malicious code upon opening the document, likely as a spearphishing attachment. The VBA code also contains a Base64 decoding function, indicating it's likely obfuscating a payload.

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
c5b47208788dc55880dd609af3eb52e7df6641e166e12d307b22d69cebcde9fc		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 36140 bytes
vbaProject_00.bin
92ddcdefa5ad1ea76b0820470105334abcb7c11b3065b1c87cbc26518655003b		 vba-project OOXML VBA project: xl/vbaProject.bin 11776 bytes

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