Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c1d286f32b7d666f…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:45:11 Authoring application: Microsoft Excel First seen: 2021-10-05
MD5: 56a3cacd22c8316ca450d645cf54aa04 SHA-1: 07c5c295ce75f95994efa36eabfb58cae1ef7c19 SHA-256: c1d286f32b7d666ffb1885a33f256e6d4010137bf4b23e5056f221d415bbb8b4
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Excel 4.0 macro sheet that contains an 'Auto_Open' defined name, indicating it will execute macros automatically when opened. The presence of dangerous formula APIs, specifically 'RUN', suggests the macro is designed to execute arbitrary commands. While the exact command is not fully recoverable from the provided evidence, the technique strongly implies a malicious intent to run an external payload.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6693 bytes
SHA-256: 9ed6c871ce50f3f23902c95e93bdfdfc56fe4f4d50c9e7210f6a1f1ecc12a6c2
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     19 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  gnZnbEiVzm
' 0018     24 LABEL : Cell Value, String Constant - aRfCXeIIS len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A180 
' 0018     25 LABEL : Cell Value, String Constant - DHlThhJpOx len=0 
' 0018     24 LABEL : Cell Value, String Constant - DokzwdXoE len=0 
' 0018     22 LABEL : Cell Value, String Constant - DxLJTnM len=0 
' 0018     26 LABEL : Cell Value, String Constant - EHZJuhCWhth len=0 
' 0018     20 LABEL : Cell Value, String Constant - FuYjb len=0 
' 0018     22 LABEL : Cell Value, String Constant - jgUXGRN len=0 
' 0018     22 LABEL : Cell Value, String Constant - kSBBzbQ len=0 
' 0018     24 LABEL : Cell Value, String Constant - kxbVqmDlL len=0 
' 0018     21 LABEL : Cell Value, String Constant - ocXcej len=0 
' 0018     22 LABEL : Cell Value, String Constant - owUUZhu len=0 
' 0018     24 LABEL : Cell Value, String Constant - qFSWcHFrW len=0 
' 0018     27 LABEL : Cell Value, String Constant - qlDJQvGUIsXS len=0 
' 0018     22 LABEL : Cell Value, String Constant - tcSYkDc len=0 
' 0018     21 LABEL : Cell Value, String Constant - tdkiMl len=0 
' 0018     22 LABEL : Cell Value, String Constant - UVYiSJu len=0 
' 0018     27 LABEL : Cell Value, String Constant - vhudRAAyBYeq len=0 
' 0018     22 LABEL : Cell Value, String Constant - VwXyOaH len=0 
' 0018     27 LABEL : Cell Value, String Constant - ythZcqKtxPGk len=0 
' 0018     27 LABEL : Cell Value, String Constant - YVYwBBWMguRi len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00f
... (truncated)