Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0e5f79a6d4bf607c…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:26:28 Authoring application: Microsoft Excel First seen: 2021-09-16
MD5: ba1e8d8940f0b88ae5ee08383898c40f SHA-1: 029e2ff47c35b8bc966005f870afa5286a77f0d0 SHA-256: 0e5f79a6d4bf607c3d12934f3a14c131f9bd93492953832e3db74a8ae8f829b6
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 macros, specifically an Auto_Open defined name. This indicates the macro will execute automatically upon opening the workbook. The presence of dangerous formula APIs, including the RUN function, suggests the macro is designed to execute arbitrary commands. This is a common technique for downloading and executing further malicious payloads.

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) 6432 bytes
SHA-256: fec0fddf3b16de0b923073d8b25ae75442a836b24c80c24d830421d5b66772c7
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 -  vuTldi
' 0018     25 LABEL : Cell Value, String Constant - aoIqfGtNrQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D137 
' 0018     20 LABEL : Cell Value, String Constant - BYNMX len=0 
' 0018     23 LABEL : Cell Value, String Constant - cPRHhvpy len=0 
' 0018     25 LABEL : Cell Value, String Constant - ENeaIQHKGd len=0 
' 0018     22 LABEL : Cell Value, String Constant - hFknpkW len=0 
' 0018     26 LABEL : Cell Value, String Constant - hOpwXWuZEcY len=0 
' 0018     23 LABEL : Cell Value, String Constant - IFnrJmZM len=0 
' 0018     21 LABEL : Cell Value, String Constant - IIVgmv len=0 
' 0018     24 LABEL : Cell Value, String Constant - izupERGwR len=0 
' 0018     20 LABEL : Cell Value, String Constant - ltQjZ len=0 
' 0018     24 LABEL : Cell Value, String Constant - OryWasWxd len=0 
' 0018     26 LABEL : Cell Value, String Constant - PpfBnuvSVbS len=0 
' 0018     25 LABEL : Cell Value, String Constant - RJluJUDwtt len=0 
' 0018     25 LABEL : Cell Value, String Constant - rqkdzNSifj len=0 
' 0018     22 LABEL : Cell Value, String Constant - sOKLoKY len=0 
' 0018     22 LABEL : Cell Value, String Constant - tsDIZTH len=0 
' 0018     23 LABEL : Cell Value, String Constant - UrXWdMRZ len=0 
' 0018     20 LABEL : Cell Value, String Constant - wuQyr len=0 
' 0018     20 LABEL : Cell Value, String Constant - ygfNB len=0 
' 0018     25 LABEL : Cell Value, String Constant - ywvJbwkCEF 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 LABEL
... (truncated)

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