Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4c00283d2752d539…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:43:22 Authoring application: Microsoft Excel First seen: 2021-10-04
MD5: be05f8d8fe9099d21b5e2fc749b09250 SHA-1: eb3ace2c9174e624fd838a4a52faf44ce91b4b46 SHA-256: 4c00283d2752d539b62072eb9300fec313972f492f0dd067c910c5fd35e3b20b
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a critical finding. This indicates an attempt to automatically execute code upon opening the workbook. The presence of dangerous formula APIs further suggests malicious intent. Without further script content, the exact payload is unknown, but the mechanism points to client-side execution of arbitrary code.

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) 6823 bytes
SHA-256: 2e2eafa52e750b99c35b0aacbb735b43624a9a362d65eccda774cde754f7afe8
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  CGrDIINEC
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D151 
' 0018     21 LABEL : Cell Value, String Constant - bSIPZu len=0 
' 0018     25 LABEL : Cell Value, String Constant - CVhTBeUrOT len=0 
' 0018     24 LABEL : Cell Value, String Constant - drYjtyYSE len=0 
' 0018     22 LABEL : Cell Value, String Constant - ElixtUM len=0 
' 0018     22 LABEL : Cell Value, String Constant - fmXdaUC len=0 
' 0018     21 LABEL : Cell Value, String Constant - GCmjQi len=0 
' 0018     26 LABEL : Cell Value, String Constant - huXPihmLXQE len=0 
' 0018     23 LABEL : Cell Value, String Constant - JbtufaqO len=0 
' 0018     25 LABEL : Cell Value, String Constant - jzhZoSMTCx len=0 
' 0018     23 LABEL : Cell Value, String Constant - mdmVwtBp len=0 
' 0018     21 LABEL : Cell Value, String Constant - MQLuBn len=0 
' 0018     25 LABEL : Cell Value, String Constant - NIkSkRVBFX len=0 
' 0018     24 LABEL : Cell Value, String Constant - rFraxgptt len=0 
' 0018     24 LABEL : Cell Value, String Constant - RQckYEJdA len=0 
' 0018     21 LABEL : Cell Value, String Constant - RtAnaE len=0 
' 0018     20 LABEL : Cell Value, String Constant - VjxWN len=0 
' 0018     22 LABEL : Cell Value, String Constant - vkxTrVp len=0 
' 0018     21 LABEL : Cell Value, String Constant - vvVICU len=0 
' 0018     26 LABEL : Cell Value, String Constant - YXievBmpImj len=0 
' 0018     24 LABEL : Cell Value, String Constant - zTiUrHNov 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 LAB
... (truncated)

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