Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a8a9f5c78b73a3ac…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:43:51 Authoring application: Microsoft Excel First seen: 2021-10-05
MD5: 0e75717977856ed68a24027d8f072c91 SHA-1: 5c93f984306dd2f0f511fc79416bf964d986b9a8 SHA-256: a8a9f5c78b73a3ace30ca76cc94067d8284ec1ad9ef2d974dcfcd6ed8c738339
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 indicating potential malicious execution. The presence of dangerous formula APIs like RUN further suggests that the macro is designed to execute arbitrary code. Without further script content or network indicators, the exact payload and family remain unknown.

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) 6596 bytes
SHA-256: 3b9b4e7eb287ec643fc6819c507645465ca2a9920ff48b3a8484d4590d84c3b2
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 -  DFDzlnPEN
' 0018     22 LABEL : Cell Value, String Constant - aNUKpAz len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F144 
' 0018     23 LABEL : Cell Value, String Constant - ChpBijyv len=0 
' 0018     22 LABEL : Cell Value, String Constant - dgiydDt len=0 
' 0018     25 LABEL : Cell Value, String Constant - dxNjfWVxLy len=0 
' 0018     25 LABEL : Cell Value, String Constant - FFvGCmbHWx len=0 
' 0018     26 LABEL : Cell Value, String Constant - FoOKTNfyAvY len=0 
' 0018     24 LABEL : Cell Value, String Constant - gzaFeCGUh len=0 
' 0018     25 LABEL : Cell Value, String Constant - KHvKHwlyvA len=0 
' 0018     23 LABEL : Cell Value, String Constant - kvfBNrnS len=0 
' 0018     20 LABEL : Cell Value, String Constant - Llnvf len=0 
' 0018     24 LABEL : Cell Value, String Constant - MLWvCpBUx len=0 
' 0018     24 LABEL : Cell Value, String Constant - NwzwQtKBM len=0 
' 0018     23 LABEL : Cell Value, String Constant - PEqIuJOr len=0 
' 0018     20 LABEL : Cell Value, String Constant - PFrgy len=0 
' 0018     20 LABEL : Cell Value, String Constant - ppUIL len=0 
' 0018     22 LABEL : Cell Value, String Constant - QIlyEcg len=0 
' 0018     26 LABEL : Cell Value, String Constant - sEujOyQMmYw len=0 
' 0018     20 LABEL : Cell Value, String Constant - WGjQF len=0 
' 0018     23 LABEL : Cell Value, String Constant - wmlvxwuU len=0 
' 0018     20 LABEL : Cell Value, String Constant - Zxanz 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 LABELS
... (truncated)

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