Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4d9979345fc69d00…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:29:50 Authoring application: Microsoft Excel First seen: 2021-09-23
MD5: 5fac4820e1f178e369e37a54bdeabfc2 SHA-1: bd393c9f709e359482fc2efcae59035ad0c64559 SHA-256: 4d9979345fc69d002b78985f38ce11eda731cd92800f4d0b59e826e74f760b6c
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. The macros utilize dangerous formula APIs, including a 'RUN' function, indicating an attempt to execute arbitrary code. This strongly suggests the macro is designed to download and execute a secondary payload.

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) 6630 bytes
SHA-256: 8cd19a8222db927400f91256465e78ad655de9b3b5de304bf5a1b5c2b14a081a
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 -  wokiMdtAoy
' 0018     24 LABEL : Cell Value, String Constant - AhVtOyeNt len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G172 
' 0018     23 LABEL : Cell Value, String Constant - DJbjvEOQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - DmeKiUXLpHi len=0 
' 0018     26 LABEL : Cell Value, String Constant - dWtqgKNTYVN len=0 
' 0018     22 LABEL : Cell Value, String Constant - DZdZIhI len=0 
' 0018     24 LABEL : Cell Value, String Constant - fuTIgKEiz len=0 
' 0018     27 LABEL : Cell Value, String Constant - hKOmOFgzJQgl len=0 
' 0018     25 LABEL : Cell Value, String Constant - KCfcpBvIiw len=0 
' 0018     27 LABEL : Cell Value, String Constant - lIwwwUeykmaZ len=0 
' 0018     21 LABEL : Cell Value, String Constant - lLfAoP len=0 
' 0018     21 LABEL : Cell Value, String Constant - mAUGfb len=0 
' 0018     27 LABEL : Cell Value, String Constant - MfPCbeGlRTKQ len=0 
' 0018     21 LABEL : Cell Value, String Constant - NLGARi len=0 
' 0018     23 LABEL : Cell Value, String Constant - qsJVyGZB len=0 
' 0018     27 LABEL : Cell Value, String Constant - rquKcknVOXCX len=0 
' 0018     21 LABEL : Cell Value, String Constant - RyMyIN len=0 
' 0018     22 LABEL : Cell Value, String Constant - sxWUwNh len=0 
' 0018     20 LABEL : Cell Value, String Constant - vnPYs len=0 
' 0018     24 LABEL : Cell Value, String Constant - xPMnYKRdF len=0 
' 0018     25 LABEL : Cell Value, String Constant - XUsLXHmFwa 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

... (truncated)

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