Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b5ffbbab81cdd2bd…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:42 Authoring application: Microsoft Excel First seen: 2021-06-30
MD5: 9dd62eb1c51d360d5a2ab727ed2300d8 SHA-1: 6c1a94604d06269462cde72e878a8df2cbcf214c SHA-256: b5ffbbab81cdd2bd8fac176c8269e1368594ded308f002e533ea3b81efa33a80
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open function. This function is designed to execute arbitrary code upon opening the workbook, leveraging dangerous formula APIs. The specific payload or target of the macro is not discernible from the provided evidence, but the mechanism clearly indicates malicious intent.

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) 6429 bytes
SHA-256: 6b1887189edad18bcbc17efae0123e37344aa93c5fecc788487b57010f026c09
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 -  XDuB
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E169 
' 0018     26 LABEL : Cell Value, String Constant - aZmOIbZWMWn len=0 
' 0018     25 LABEL : Cell Value, String Constant - bhIbUqfBgY len=0 
' 0018     20 LABEL : Cell Value, String Constant - BzXaf len=0 
' 0018     26 LABEL : Cell Value, String Constant - cdMrswVRJOe len=0 
' 0018     26 LABEL : Cell Value, String Constant - GBLnlteuGsG len=0 
' 0018     24 LABEL : Cell Value, String Constant - iUyMTBnHL len=0 
' 0018     27 LABEL : Cell Value, String Constant - jVDleHExqgaA len=0 
' 0018     23 LABEL : Cell Value, String Constant - kLwVToLE len=0 
' 0018     21 LABEL : Cell Value, String Constant - kZcZnv len=0 
' 0018     20 LABEL : Cell Value, String Constant - MMzxj len=0 
' 0018     26 LABEL : Cell Value, String Constant - MYkfJvvSBjy len=0 
' 0018     23 LABEL : Cell Value, String Constant - NCagSfJN len=0 
' 0018     26 LABEL : Cell Value, String Constant - oYjobHHxYOA len=0 
' 0018     23 LABEL : Cell Value, String Constant - pMFMVALi len=0 
' 0018     22 LABEL : Cell Value, String Constant - QxHFndc len=0 
' 0018     20 LABEL : Cell Value, String Constant - uLQgv len=0 
' 0018     25 LABEL : Cell Value, String Constant - vYkqhCObhK len=0 
' 0018     23 LABEL : Cell Value, String Constant - wuLBBJKL len=0 
' 0018     27 LABEL : Cell Value, String Constant - XERZEfoVQtAx len=0 
' 0018     26 LABEL : Cell Value, String Constant - ZeitKOsrmjq 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
' 0
... (truncated)

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