Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 eab3ae28c5ad89a3…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:44:10 Authoring application: Microsoft Excel First seen: 2020-12-25
MD5: 1ccc68c68febe167398498f8dea86488 SHA-1: f1b49ee19a7bfe1b059f460a0c2eff355cae9dd4 SHA-256: eab3ae28c5ad89a39cc2ff40b4efd67971da454e0dcfac1781ba408ce1c566eb
140 Risk Score

Malware Insights

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

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open defined name. This indicates an attempt to automatically execute code when the workbook is opened. The presence of dangerous formula APIs like RUN suggests the macro is intended to download and execute a secondary payload, a common technique for malware delivery.

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) 6466 bytes
SHA-256: c93eac49a7621547158753b8df566ae2bd9061c208990fa6eaaa9ef773c7ae60
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  CcuFWV
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H169 
' 0018     23 LABEL : Cell Value, String Constant - CmSVvXDe len=0 
' 0018     23 LABEL : Cell Value, String Constant - DSNODSsx len=0 
' 0018     21 LABEL : Cell Value, String Constant - EWKNDm len=0 
' 0018     21 LABEL : Cell Value, String Constant - gdaAqk len=0 
' 0018     22 LABEL : Cell Value, String Constant - GfvtoAL len=0 
' 0018     25 LABEL : Cell Value, String Constant - GnJkmbqGVo len=0 
' 0018     22 LABEL : Cell Value, String Constant - grWwzsX len=0 
' 0018     21 LABEL : Cell Value, String Constant - GtZeZE len=0 
' 0018     22 LABEL : Cell Value, String Constant - iarChpM len=0 
' 0018     25 LABEL : Cell Value, String Constant - kgzNLmFFmk len=0 
' 0018     21 LABEL : Cell Value, String Constant - MHrJQH len=0 
' 0018     23 LABEL : Cell Value, String Constant - pZpwtGMw len=0 
' 0018     27 LABEL : Cell Value, String Constant - rePgdszbpOWN len=0 
' 0018     27 LABEL : Cell Value, String Constant - rWqHTVAqLhlZ len=0 
' 0018     25 LABEL : Cell Value, String Constant - TfPWFBqfko len=0 
' 0018     23 LABEL : Cell Value, String Constant - vcdpYdcW len=0 
' 0018     24 LABEL : Cell Value, String Constant - xnrhyMqfO len=0 
' 0018     27 LABEL : Cell Value, String Constant - xoLhMRGpKcgD len=0 
' 0018     23 LABEL : Cell Value, String Constant - yNdTMSfp len=0 
' 0018     21 LABEL : Cell Value, String Constant - ZImbhA 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
' 00fd     10 
... (truncated)

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