Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c36f4f24122eb0e9…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-27 11:42:20 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: 76a8303689d7b73c99aa30f999eafc5e SHA-1: 539f9fc9f212bb1442cffc6c038f48d7da46bb4c SHA-256: c36f4f24122eb0e986ab729914730f6bc2d5cd4bfd49679a2e6e72adab0905a5
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 automatically when the workbook is opened. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code, likely to download and run a second-stage payload. No specific family could be identified.

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) 6707 bytes
SHA-256: a4f56a9353dcbd5092f0fe6dd43a3db584e81e93a8dd71e0693035dc496dba91
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 -  AFErYF
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B147 
' 0018     21 LABEL : Cell Value, String Constant - BJSDMF len=0 
' 0018     27 LABEL : Cell Value, String Constant - bWPjIovyownx len=0 
' 0018     26 LABEL : Cell Value, String Constant - EjrDYYZrWHl len=0 
' 0018     24 LABEL : Cell Value, String Constant - fImJyAzxT len=0 
' 0018     23 LABEL : Cell Value, String Constant - hIntRAxw len=0 
' 0018     23 LABEL : Cell Value, String Constant - MNMSRGrs len=0 
' 0018     22 LABEL : Cell Value, String Constant - oDbdUws len=0 
' 0018     23 LABEL : Cell Value, String Constant - PLSAqmUb len=0 
' 0018     25 LABEL : Cell Value, String Constant - qHltYIFKUr len=0 
' 0018     24 LABEL : Cell Value, String Constant - qLbcHOJEL len=0 
' 0018     25 LABEL : Cell Value, String Constant - qVuBZqNVgc len=0 
' 0018     24 LABEL : Cell Value, String Constant - RZAmBajZu len=0 
' 0018     25 LABEL : Cell Value, String Constant - SWCRJbJRtQ len=0 
' 0018     25 LABEL : Cell Value, String Constant - TjOOWLnNew len=0 
' 0018     27 LABEL : Cell Value, String Constant - tSiVCxqNyNJV len=0 
' 0018     21 LABEL : Cell Value, String Constant - uunbRw len=0 
' 0018     26 LABEL : Cell Value, String Constant - XeYwsaPWvbd len=0 
' 0018     23 LABEL : Cell Value, String Constant - YHXKcbkI len=0 
' 0018     26 LABEL : Cell Value, String Constant - YlxdeVXLNKc len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZTuexOIA 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/ S
... (truncated)

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