Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5e3165808876b975…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:44:38 Authoring application: Microsoft Excel First seen: 2021-10-16
MD5: 81308239aa682cfa6e4f44c33ee5b5aa SHA-1: 333ebdc3b349ff071fb6d75ac4d26c05d950e4d6 SHA-256: 5e3165808876b9758310f6cfaac16a5d37c72afdb55b286454c1abe75a6822fa
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro sheet that contains an Auto_Open defined name, indicating it will execute macros automatically upon opening. The critical heuristic firings confirm the presence of dangerous formula APIs, specifically related to execution, suggesting the macro is designed to run arbitrary commands. No specific family could be identified, but the technique is consistent with macro-based malware.

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) 6519 bytes
SHA-256: d51bb9c75bce94482488e699c7cb03d58b9fff93ba92b1661bace63672213e01
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  IGdwjqN
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I147 
' 0018     21 LABEL : Cell Value, String Constant - CEzaAz len=0 
' 0018     23 LABEL : Cell Value, String Constant - EwJtvhOJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - fcQsQtlNekZ len=0 
' 0018     27 LABEL : Cell Value, String Constant - ftSpWWehyOoq len=0 
' 0018     21 LABEL : Cell Value, String Constant - Gtaeuk len=0 
' 0018     21 LABEL : Cell Value, String Constant - jeKMdD len=0 
' 0018     25 LABEL : Cell Value, String Constant - mhVvAepQla len=0 
' 0018     22 LABEL : Cell Value, String Constant - nkIfEts len=0 
' 0018     20 LABEL : Cell Value, String Constant - oBiqv len=0 
' 0018     21 LABEL : Cell Value, String Constant - oCSgbm len=0 
' 0018     22 LABEL : Cell Value, String Constant - ocVTbKV len=0 
' 0018     22 LABEL : Cell Value, String Constant - SfaZWzk len=0 
' 0018     20 LABEL : Cell Value, String Constant - Unqmo len=0 
' 0018     21 LABEL : Cell Value, String Constant - UvgSxl len=0 
' 0018     27 LABEL : Cell Value, String Constant - vVypQhNGgIKU len=0 
' 0018     27 LABEL : Cell Value, String Constant - WdZDAOlAQZKq len=0 
' 0018     27 LABEL : Cell Value, String Constant - WisuwGGTZBXe len=0 
' 0018     22 LABEL : Cell Value, String Constant - xIPmVLJ len=0 
' 0018     25 LABEL : Cell Value, String Constant - xwmHysPDva len=0 
' 0018     20 LABEL : Cell Value, String Constant - ZWjXv 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 LABEL
... (truncated)

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