Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 579bd0fdd67e2384…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:47:02 Authoring application: Microsoft Excel First seen: 2021-09-23
MD5: 097ff7a22a24e7d42a239cab1102674f SHA-1: a722a876dd526c1cd50df95c41fd6f6977ef4f79 SHA-256: 579bd0fdd67e2384187edbe2cbb75419def83ea45dc826d7f4cd6695bababfbb
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, suggesting an attempt to automatically execute code upon opening the workbook. The macro sheet contains a reference to 'Auto_Open' and uses dangerous formula APIs, including 'RUN', which is commonly used to launch executables. The document body contains obfuscated text, likely part of the macro's execution flow.

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) 6661 bytes
SHA-256: 31dc50bbffb5a6829ab0c5c2661bb4fb7cf2eb8e37520b91f9d681bae6457455
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  CofMVY
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C193 
' 0018     21 LABEL : Cell Value, String Constant - chupCP len=0 
' 0018     25 LABEL : Cell Value, String Constant - CyfpgKbeML len=0 
' 0018     27 LABEL : Cell Value, String Constant - eWEZrpLywmhg len=0 
' 0018     21 LABEL : Cell Value, String Constant - GpQFtV len=0 
' 0018     25 LABEL : Cell Value, String Constant - hBBnpnXSek len=0 
' 0018     24 LABEL : Cell Value, String Constant - hFQrScBRM len=0 
' 0018     24 LABEL : Cell Value, String Constant - HxpSXiMPT len=0 
' 0018     20 LABEL : Cell Value, String Constant - iVTOB len=0 
' 0018     24 LABEL : Cell Value, String Constant - LSZfpagKn len=0 
' 0018     26 LABEL : Cell Value, String Constant - lWonSYMNAgp len=0 
' 0018     22 LABEL : Cell Value, String Constant - mzDYEZq len=0 
' 0018     24 LABEL : Cell Value, String Constant - nKPebxavq len=0 
' 0018     20 LABEL : Cell Value, String Constant - oeNIB len=0 
' 0018     20 LABEL : Cell Value, String Constant - OIfoC len=0 
' 0018     20 LABEL : Cell Value, String Constant - ozDNN len=0 
' 0018     20 LABEL : Cell Value, String Constant - QQgLg len=0 
' 0018     26 LABEL : Cell Value, String Constant - sOlIkZKAGpq len=0 
' 0018     26 LABEL : Cell Value, String Constant - TlKyUCGnWqB len=0 
' 0018     24 LABEL : Cell Value, String Constant - YbGXBrpzK len=0 
' 0018     24 LABEL : Cell Value, String Constant - YtELmAMAk 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 LAB
... (truncated)

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