Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 1c1ae6efbc8dcc94…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:39:12 Authoring application: Microsoft Excel First seen: 2021-06-20
MD5: 151f9b90272bcbbff0886ca4180a3450 SHA-1: 228fe171c562f8c0a8f7334cd5d6cc77f36ff89d SHA-256: 1c1ae6efbc8dcc940736d1f587bda9fc5b27027864951f91e6d76124aa086943
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro sheet containing an Auto_Open function, which is a critical finding indicating malicious intent. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. This is a common technique for downloading and executing further malicious payloads.

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) 6750 bytes
SHA-256: b1ad639141f5c453c6de3d82d93e7424a7697263438e1b9a83b6bfca128ebd52
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 -  sYZIxekcM
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G156 
' 0018     20 LABEL : Cell Value, String Constant - cqcYl len=0 
' 0018     21 LABEL : Cell Value, String Constant - dvUHuF len=0 
' 0018     21 LABEL : Cell Value, String Constant - dXCXNu len=0 
' 0018     22 LABEL : Cell Value, String Constant - FFRyCPu len=0 
' 0018     27 LABEL : Cell Value, String Constant - jtyoInwOncEn len=0 
' 0018     21 LABEL : Cell Value, String Constant - MTfRHI len=0 
' 0018     23 LABEL : Cell Value, String Constant - MWrxgHjZ len=0 
' 0018     22 LABEL : Cell Value, String Constant - oEJeSks len=0 
' 0018     25 LABEL : Cell Value, String Constant - OPnktOLFJa len=0 
' 0018     22 LABEL : Cell Value, String Constant - PffCPCt len=0 
' 0018     22 LABEL : Cell Value, String Constant - PJdjYbK len=0 
' 0018     20 LABEL : Cell Value, String Constant - pjTnv len=0 
' 0018     20 LABEL : Cell Value, String Constant - qwtgy len=0 
' 0018     26 LABEL : Cell Value, String Constant - tKeANWrJWeB len=0 
' 0018     23 LABEL : Cell Value, String Constant - tTobBWzw len=0 
' 0018     23 LABEL : Cell Value, String Constant - VFmhujzT len=0 
' 0018     23 LABEL : Cell Value, String Constant - WiTmproz len=0 
' 0018     24 LABEL : Cell Value, String Constant - xQnbRAGKd len=0 
' 0018     21 LABEL : Cell Value, String Constant - Xvppcq len=0 
' 0018     27 LABEL : Cell Value, String Constant - YbSYwQKYptQt 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 :
... (truncated)

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