Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 39643c86f43ac570…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:41:42 Authoring application: Microsoft Excel First seen: 2021-07-07
MD5: 642eb380008d812a6e65e1e6c7fd7156 SHA-1: 3350d66882966fa0608ae42ba9cf5439c008b7f1 SHA-256: 39643c86f43ac570d6e75b84f5ff9b093b914b5a5825a313c3643d750be51221
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 within Office documents. The `RUN` function API is also present, suggesting the macro attempts to execute an external program or script. The document body contains heavily obfuscated text, further indicating 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) 6749 bytes
SHA-256: 07ff8e87c0692d26f34ad81190b29287bfd98e0164e75bd839345dae3f9aa87d
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  wVMAWXpX
' 0018     25 LABEL : Cell Value, String Constant - AheZQtVUaP len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C140 
' 0018     25 LABEL : Cell Value, String Constant - ceNnyFEdzR len=0 
' 0018     23 LABEL : Cell Value, String Constant - cXvyWPbs len=0 
' 0018     27 LABEL : Cell Value, String Constant - eKgsKRQlgseZ len=0 
' 0018     26 LABEL : Cell Value, String Constant - fvpqCYYnCRr len=0 
' 0018     22 LABEL : Cell Value, String Constant - hgPljgc len=0 
' 0018     20 LABEL : Cell Value, String Constant - iNNor len=0 
' 0018     22 LABEL : Cell Value, String Constant - JzaLKNg len=0 
' 0018     20 LABEL : Cell Value, String Constant - LPzfW len=0 
' 0018     22 LABEL : Cell Value, String Constant - lQtgLvH len=0 
' 0018     20 LABEL : Cell Value, String Constant - OOhNY len=0 
' 0018     24 LABEL : Cell Value, String Constant - PbRvllmbt len=0 
' 0018     25 LABEL : Cell Value, String Constant - sgMPjtYMAW len=0 
' 0018     25 LABEL : Cell Value, String Constant - sRFkjKyhXH len=0 
' 0018     22 LABEL : Cell Value, String Constant - THnJxPZ len=0 
' 0018     24 LABEL : Cell Value, String Constant - veTGmWKgh len=0 
' 0018     27 LABEL : Cell Value, String Constant - vlKTHcRpZlfw len=0 
' 0018     23 LABEL : Cell Value, String Constant - wiHgaRLJ len=0 
' 0018     24 LABEL : Cell Value, String Constant - YloyQQfHh len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZnUuGrZ 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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