Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c7af42906ef51832…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:36:10 Authoring application: Microsoft Excel First seen: 2021-09-23
MD5: e5ba5ddb6b18378e11d4788af35db347 SHA-1: 710157d6c92ece9e7c748e240a7de3deb7c230aa SHA-256: c7af42906ef5183243f86f030e2c0591d40e144b9c92d06c686afae984887001
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, which is a critical finding. This indicates the macro will execute automatically when the workbook is opened. The presence of dangerous formula APIs like RUN suggests the macro is intended to execute arbitrary code, likely downloading and running 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) 6769 bytes
SHA-256: a237c8530de87397c6f25fb0666a59ade86050510494fcec777fd7b2912cb5b1
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 -  kPTgArSrDp
' 0018     25 LABEL : Cell Value, String Constant - AgISqVRxlh len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H191 
' 0018     25 LABEL : Cell Value, String Constant - cJwFLCfZyJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - coTnsxoS len=0 
' 0018     27 LABEL : Cell Value, String Constant - FaQAjKKptQKz len=0 
' 0018     22 LABEL : Cell Value, String Constant - GfzsBzP len=0 
' 0018     26 LABEL : Cell Value, String Constant - ICWpMLWYvmR len=0 
' 0018     22 LABEL : Cell Value, String Constant - iluXkEI len=0 
' 0018     20 LABEL : Cell Value, String Constant - jFMzd len=0 
' 0018     23 LABEL : Cell Value, String Constant - JXlFPjEW len=0 
' 0018     22 LABEL : Cell Value, String Constant - knGchwA len=0 
' 0018     26 LABEL : Cell Value, String Constant - ngLXToPwrVQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - pAUxrEmjxKF len=0 
' 0018     26 LABEL : Cell Value, String Constant - pTrjiUFhZxY len=0 
' 0018     23 LABEL : Cell Value, String Constant - TUAQeoRg len=0 
' 0018     26 LABEL : Cell Value, String Constant - tVnFOPLpPYX len=0 
' 0018     20 LABEL : Cell Value, String Constant - WkDjq len=0 
' 0018     26 LABEL : Cell Value, String Constant - wSSHGFDNORK len=0 
' 0018     25 LABEL : Cell Value, String Constant - xAUpbpyjhX len=0 
' 0018     27 LABEL : Cell Value, String Constant - xRFdiRgfiuNQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - YLimfvx 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
... (truncated)

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