Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4478acfc62f4443e…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:38:31 Authoring application: Microsoft Excel First seen: 2021-06-30
MD5: bd826ad93bdb7efd417b9bf05f029557 SHA-1: 8aa82dcaf8ba4ab9cf118e4b73ac20dfe757da87 SHA-256: 4478acfc62f4443edf5caa2cc73e27b0941abbe3cf18c1ea5b9539759df9f4e0
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 function, which is a known method for executing malicious code. The macro sheet contains references to dangerous formula APIs, specifically 'RUN', suggesting it is designed to execute arbitrary commands. The document body contains heavily obfuscated text, which is typical for macro-based malware attempting to hide its true 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) 6567 bytes
SHA-256: 3804f1dd2b26645454a0debf3735a566ca44b26d29b47539919422a592b78fd7
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  EBNxIjGmj
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H168 
' 0018     24 LABEL : Cell Value, String Constant - ByEFzBObF len=0 
' 0018     20 LABEL : Cell Value, String Constant - edBFW len=0 
' 0018     21 LABEL : Cell Value, String Constant - GxVbef len=0 
' 0018     27 LABEL : Cell Value, String Constant - INMXJigKDFEH len=0 
' 0018     24 LABEL : Cell Value, String Constant - KifUkLpIV len=0 
' 0018     27 LABEL : Cell Value, String Constant - lUedYxNMlTyU len=0 
' 0018     26 LABEL : Cell Value, String Constant - MEhiltIJkHb len=0 
' 0018     23 LABEL : Cell Value, String Constant - PdAddQZV len=0 
' 0018     21 LABEL : Cell Value, String Constant - pdnSZa len=0 
' 0018     21 LABEL : Cell Value, String Constant - pNDALd len=0 
' 0018     24 LABEL : Cell Value, String Constant - qhcWAbhGX len=0 
' 0018     20 LABEL : Cell Value, String Constant - qYFZy len=0 
' 0018     22 LABEL : Cell Value, String Constant - RfvaGMP len=0 
' 0018     21 LABEL : Cell Value, String Constant - syNWnd len=0 
' 0018     22 LABEL : Cell Value, String Constant - vQhvPkU len=0 
' 0018     27 LABEL : Cell Value, String Constant - wIqnLlHiiPgM len=0 
' 0018     21 LABEL : Cell Value, String Constant - woJuSX len=0 
' 0018     26 LABEL : Cell Value, String Constant - WzqzcdAXoxd len=0 
' 0018     24 LABEL : Cell Value, String Constant - XevnhFcxi len=0 
' 0018     25 LABEL : Cell Value, String Constant - YvjDqvxRSr 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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