Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c58e00c6edb1bf73…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:46:40 Authoring application: Microsoft Excel First seen: 2021-09-24
MD5: 927b1aa1677ce98177da9ec18ebffd35 SHA-1: 67f1eea8edf0a0086f2deb8e4b83e880fc7a1658 SHA-256: c58e00c6edb1bf7345c4f94b56f636fbe487478d120075281827e9268a6978fe
140 Risk Score

Malware Insights

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

The file is an Excel workbook containing Excel 4.0 (XLM) macros. Critical heuristics indicate the presence of an Auto_Open defined name, which is a common mechanism for automatically executing malicious code when the workbook is opened. The XLM macros also utilize dangerous formula APIs, suggesting an intent to perform actions beyond standard spreadsheet operations.

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) 6603 bytes
SHA-256: 66e3a169d7f257ff70856bbe6a6c1b7ba86cb5285af7b5e79e44a691e269af75
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 -  XBI
' 0018     24 LABEL : Cell Value, String Constant - AddunkSkn len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G193 
' 0018     26 LABEL : Cell Value, String Constant - brKTxfqxXFz len=0 
' 0018     26 LABEL : Cell Value, String Constant - DgjBilrrxqo len=0 
' 0018     22 LABEL : Cell Value, String Constant - drwrDOv len=0 
' 0018     23 LABEL : Cell Value, String Constant - dvvAACTo len=0 
' 0018     25 LABEL : Cell Value, String Constant - gCXcrTijPx len=0 
' 0018     23 LABEL : Cell Value, String Constant - GKEuFtQe len=0 
' 0018     20 LABEL : Cell Value, String Constant - grRFB len=0 
' 0018     24 LABEL : Cell Value, String Constant - IQIgsmUbJ len=0 
' 0018     25 LABEL : Cell Value, String Constant - lIYjbhiViv len=0 
' 0018     23 LABEL : Cell Value, String Constant - ludjbWuq len=0 
' 0018     26 LABEL : Cell Value, String Constant - MFZnvCdXcOM len=0 
' 0018     25 LABEL : Cell Value, String Constant - MQMIAMAjGi len=0 
' 0018     21 LABEL : Cell Value, String Constant - ohUbLF len=0 
' 0018     26 LABEL : Cell Value, String Constant - oiDJIiSBbcZ len=0 
' 0018     27 LABEL : Cell Value, String Constant - uQTXqpznjvJC len=0 
' 0018     24 LABEL : Cell Value, String Constant - VVyohxtDe len=0 
' 0018     27 LABEL : Cell Value, String Constant - wejZpVceLtJQ len=0 
' 0018     27 LABEL : Cell Value, String Constant - wTVMVjrIOeCE len=0 
' 0018     24 LABEL : Cell Value, String Constant - yNSerrDAw 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/
... (truncated)

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