Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6dfbba62aef64c3e…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:39:02 Authoring application: Microsoft Excel First seen: 2021-06-04
MD5: 3348b89c408c6ee82d7edf59a52e05dd SHA-1: cebd7c97915c992ce70046c4e16c8aa6ea300c96 SHA-256: 6dfbba62aef64c3e68fb5ef0246f4a245b75ddd72faeacab5c5ac31a31af807e
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of an Excel 4.0 macro sheet with an Auto_Open defined name and dangerous formula APIs, specifically the RUN function. This suggests the file is designed to automatically execute a payload upon opening. No specific family could be identified, but the technique points to a macro-based execution.

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) 6684 bytes
SHA-256: a9f19740ebd8182a7bf410031c1a6e1d72664dbbe86d87167b3cfbe34b0d67a8
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 -  YDkU
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D172 
' 0018     20 LABEL : Cell Value, String Constant - BAiiE len=0 
' 0018     26 LABEL : Cell Value, String Constant - BIdBOfYZytW len=0 
' 0018     24 LABEL : Cell Value, String Constant - dDFhSropj len=0 
' 0018     27 LABEL : Cell Value, String Constant - dMjKitOmowsl len=0 
' 0018     21 LABEL : Cell Value, String Constant - EBvrbm len=0 
' 0018     27 LABEL : Cell Value, String Constant - fxvmryJXZobc len=0 
' 0018     27 LABEL : Cell Value, String Constant - GbJBXBUreKNY len=0 
' 0018     22 LABEL : Cell Value, String Constant - hVqiTFs len=0 
' 0018     25 LABEL : Cell Value, String Constant - jAAWTVaXEV len=0 
' 0018     24 LABEL : Cell Value, String Constant - LOTDTxfjk len=0 
' 0018     23 LABEL : Cell Value, String Constant - lXdNgyCp len=0 
' 0018     24 LABEL : Cell Value, String Constant - MUfhPcpeb len=0 
' 0018     20 LABEL : Cell Value, String Constant - OLrSN len=0 
' 0018     26 LABEL : Cell Value, String Constant - QTVTbLIZyQp len=0 
' 0018     23 LABEL : Cell Value, String Constant - REsEYEmL len=0 
' 0018     24 LABEL : Cell Value, String Constant - TVeiLRPdM len=0 
' 0018     25 LABEL : Cell Value, String Constant - UBKBEcCSDI len=0 
' 0018     22 LABEL : Cell Value, String Constant - uBOEBME len=0 
' 0018     24 LABEL : Cell Value, String Constant - XKhgyNuLm len=0 
' 0018     27 LABEL : Cell Value, String Constant - xPnXqvEPOHQI 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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