Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e85142d644156c8d…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:42:23 Authoring application: Microsoft Excel First seen: 2021-09-22
MD5: 662824c95d9e8b0eb0903ddb7cde24dc SHA-1: 47ed5d572e1ecfe54c02c06dbd8d9dc182881417 SHA-256: e85142d644156c8d8de6d8348673f2fad9ecf82d1db0959079dcad057c53426e
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, which is a common technique for executing malicious code upon opening the document. The macro sheet contains numerous string constants and references to dangerous formula APIs, suggesting it is designed to download and execute a secondary payload. No specific family could be identified.

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) 6804 bytes
SHA-256: dc30202facff75afc8c5f5ca337f96e72bd3ca66d2e6b8e76ec12da7ce8d3500
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  DFsiqrWWftq
' 0018     24 LABEL : Cell Value, String Constant - acTsElhtN len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I178 
' 0018     26 LABEL : Cell Value, String Constant - ceLpfmuSmzS len=0 
' 0018     20 LABEL : Cell Value, String Constant - cjGte len=0 
' 0018     21 LABEL : Cell Value, String Constant - DBuBmU len=0 
' 0018     27 LABEL : Cell Value, String Constant - dCQLCNsTmGgu len=0 
' 0018     23 LABEL : Cell Value, String Constant - DHfhkYcL len=0 
' 0018     20 LABEL : Cell Value, String Constant - FSIki len=0 
' 0018     20 LABEL : Cell Value, String Constant - giEMM len=0 
' 0018     20 LABEL : Cell Value, String Constant - GLIqF len=0 
' 0018     20 LABEL : Cell Value, String Constant - HCjlG len=0 
' 0018     26 LABEL : Cell Value, String Constant - hcKdcaBrIdw len=0 
' 0018     22 LABEL : Cell Value, String Constant - HgYFdcx len=0 
' 0018     25 LABEL : Cell Value, String Constant - JZEqNaOXkw len=0 
' 0018     26 LABEL : Cell Value, String Constant - kwBJQmqmEuF len=0 
' 0018     20 LABEL : Cell Value, String Constant - lbZRu len=0 
' 0018     20 LABEL : Cell Value, String Constant - MDmxV len=0 
' 0018     24 LABEL : Cell Value, String Constant - nZBriKgPz len=0 
' 0018     22 LABEL : Cell Value, String Constant - PjvzGFc len=0 
' 0018     25 LABEL : Cell Value, String Constant - YHUyyvMhzX len=0 
' 0018     20 LABEL : Cell Value, String Constant - YkDXW 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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