Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9c5f11f9e3b70595…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:47:13 Authoring application: Microsoft Excel First seen: 2021-10-01
MD5: 1253d2612ec56ef4c08da4072da60641 SHA-1: 4edfdad8397b66fe46b45a0dc9ac0c1abbe4ab74 SHA-256: 9c5f11f9e3b7059509bbb289c4b7915bea086b01b3c1d50ed1a781e1186f17d3
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 (XLM) macros, specifically an Auto_Open macro. This indicates the file is designed to automatically execute code upon opening. The presence of dangerous formula APIs like RUN suggests the macro is intended to download and execute a secondary payload, a common technique for malware delivery.

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) 6371 bytes
SHA-256: d6d653a0d001b78f6406c26b8beaac5b7c63693e1ac2d85c9e40a1f8152ad930
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  HpJf
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A181 
' 0018     25 LABEL : Cell Value, String Constant - CbEUqnPgoq len=0 
' 0018     25 LABEL : Cell Value, String Constant - CDhVdGytRg len=0 
' 0018     24 LABEL : Cell Value, String Constant - DhSyqBWew len=0 
' 0018     24 LABEL : Cell Value, String Constant - DYweYrnZX len=0 
' 0018     21 LABEL : Cell Value, String Constant - kkrpBK len=0 
' 0018     24 LABEL : Cell Value, String Constant - KLOxhJYlA len=0 
' 0018     20 LABEL : Cell Value, String Constant - LKYcb len=0 
' 0018     22 LABEL : Cell Value, String Constant - LLToqwb len=0 
' 0018     24 LABEL : Cell Value, String Constant - lOqkGQAgl len=0 
' 0018     23 LABEL : Cell Value, String Constant - maCyhHoS len=0 
' 0018     20 LABEL : Cell Value, String Constant - NjLcF len=0 
' 0018     27 LABEL : Cell Value, String Constant - pEAkkrvBCLnw len=0 
' 0018     22 LABEL : Cell Value, String Constant - PvCflWm len=0 
' 0018     22 LABEL : Cell Value, String Constant - qHmubqW len=0 
' 0018     25 LABEL : Cell Value, String Constant - qwLPABWJfa len=0 
' 0018     23 LABEL : Cell Value, String Constant - rUqIvhnZ len=0 
' 0018     23 LABEL : Cell Value, String Constant - uKFyUCXG len=0 
' 0018     20 LABEL : Cell Value, String Constant - VybmY len=0 
' 0018     20 LABEL : Cell Value, String Constant - XxUOe len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZqUPuaFF 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 LABELSST : 
... (truncated)

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