Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 51224335a81c7a8a…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:29:59 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: 1d454bc52bedcaac6a14a454d9ff7e81 SHA-1: 1d18e6be341ba77a04ce163d6febc7f229d9b5bb SHA-256: 51224335a81c7a8a9510de89d7e6de0161037b72db879d051cac4bdab26b7692
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 defined name, which is a common technique for executing malicious code upon opening the document. The `RUN=0` formula API suggests the macro is designed to execute arbitrary commands or download further payloads. The extensive obfuscated text in the document body further supports the 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) 6378 bytes
SHA-256: cef082c22a8522edf07eb1d5d18c1af41930bcfb10340e3de07b6360ee0c1322
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 -  KosD
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I182 
' 0018     23 LABEL : Cell Value, String Constant - bAxwAFOi len=0 
' 0018     21 LABEL : Cell Value, String Constant - ECMYla len=0 
' 0018     22 LABEL : Cell Value, String Constant - FqzRqCk len=0 
' 0018     27 LABEL : Cell Value, String Constant - GCLHaqdpUPYm len=0 
' 0018     22 LABEL : Cell Value, String Constant - gJCXuct len=0 
' 0018     20 LABEL : Cell Value, String Constant - gVhDN len=0 
' 0018     20 LABEL : Cell Value, String Constant - hcfGm len=0 
' 0018     23 LABEL : Cell Value, String Constant - JWoedTjV len=0 
' 0018     22 LABEL : Cell Value, String Constant - KWVjIwJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - LwlNw len=0 
' 0018     27 LABEL : Cell Value, String Constant - ogtvANwozEAH len=0 
' 0018     21 LABEL : Cell Value, String Constant - OTfppF len=0 
' 0018     20 LABEL : Cell Value, String Constant - pkdkk len=0 
' 0018     24 LABEL : Cell Value, String Constant - QDsYwkekH len=0 
' 0018     23 LABEL : Cell Value, String Constant - QFJaFkTR len=0 
' 0018     23 LABEL : Cell Value, String Constant - qOyHisGG len=0 
' 0018     26 LABEL : Cell Value, String Constant - wAodjkbeimW len=0 
' 0018     24 LABEL : Cell Value, String Constant - XsIPhzGrX len=0 
' 0018     23 LABEL : Cell Value, String Constant - YcuDSXtk len=0 
' 0018     26 LABEL : Cell Value, String Constant - zZYakVvddXz 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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