Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 129ef130e56aab74…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:38:59 Authoring application: Microsoft Excel First seen: 2021-07-10
MD5: d4c9f7d60c160d31345f230e1c5f1062 SHA-1: 98d4a1d9e2d62a2d4f0272855114cdff95f553e9 SHA-256: 129ef130e56aab7490c6b9788f6004390636c0d4e4850a943fb8122606b7045b
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The file is an Excel document containing Excel 4.0 macros, specifically an Auto_Open defined name. This indicates the document is designed to automatically execute malicious 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 initial access via spearphishing attachments.

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) 6712 bytes
SHA-256: c194ca5562a8adbc31a20db77e13a50dfd3ab79c3993c9d84150914088854a98
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  LkkXNhe
' 0018     20 LABEL : Cell Value, String Constant - amJla len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D182 
' 0018     25 LABEL : Cell Value, String Constant - bMugENTjAa len=0 
' 0018     22 LABEL : Cell Value, String Constant - bNgQfTB len=0 
' 0018     27 LABEL : Cell Value, String Constant - bUizKNZVdOel len=0 
' 0018     24 LABEL : Cell Value, String Constant - epEMLkSUJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - exYLRQ len=0 
' 0018     21 LABEL : Cell Value, String Constant - eycvXo len=0 
' 0018     26 LABEL : Cell Value, String Constant - hkvKaGGYikG len=0 
' 0018     24 LABEL : Cell Value, String Constant - JqOJygpDI len=0 
' 0018     23 LABEL : Cell Value, String Constant - LGnGsmAT len=0 
' 0018     21 LABEL : Cell Value, String Constant - NHvbFy len=0 
' 0018     24 LABEL : Cell Value, String Constant - oPVCLJSEf len=0 
' 0018     21 LABEL : Cell Value, String Constant - plyDEZ len=0 
' 0018     27 LABEL : Cell Value, String Constant - QhNFjXBVRYOr len=0 
' 0018     24 LABEL : Cell Value, String Constant - ROxNwlBIh len=0 
' 0018     27 LABEL : Cell Value, String Constant - vATsSHmiCiQe len=0 
' 0018     27 LABEL : Cell Value, String Constant - VDQibRvuccyz len=0 
' 0018     23 LABEL : Cell Value, String Constant - xpiZiDee len=0 
' 0018     20 LABEL : Cell Value, String Constant - ZMzOw len=0 
' 0018     23 LABEL : Cell Value, String Constant - zRNlQZcN 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   
... (truncated)

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