Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 811440d7f758cd6e…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:47:10 Authoring application: Microsoft Excel First seen: 2021-07-07
MD5: c3a012b8f9960d93285aa5a72f93b5f6 SHA-1: 5c9c63466d2b5a515c40400e7c849ee9995d25d0 SHA-256: 811440d7f758cd6ef0b32fc6f51897f6221b5fe20b8305a238344e74615f9068
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 (XLM) macros, indicated by critical heuristic firings for OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN. The presence of an Auto_Open defined name suggests that the macro is designed to execute automatically upon opening the workbook. The dangerous formula APIs used in the macro indicate it's intended to perform malicious actions, such as downloading and executing a secondary 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) 6767 bytes
SHA-256: d5b816e5c822f7fc836f06e6930abe59573c6eafb1487cd041b3def2866915e5
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  XtTJtgVv
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H187 
' 0018     26 LABEL : Cell Value, String Constant - CaawXMLQjNx len=0 
' 0018     23 LABEL : Cell Value, String Constant - cBRvriyd len=0 
' 0018     26 LABEL : Cell Value, String Constant - dfnJnYNyhAp len=0 
' 0018     24 LABEL : Cell Value, String Constant - ejREGjqVJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - ErxAwK len=0 
' 0018     21 LABEL : Cell Value, String Constant - JYweoD len=0 
' 0018     24 LABEL : Cell Value, String Constant - NjqAAmQRb len=0 
' 0018     24 LABEL : Cell Value, String Constant - nUsAqIzSj len=0 
' 0018     24 LABEL : Cell Value, String Constant - OItmkAKvb len=0 
' 0018     26 LABEL : Cell Value, String Constant - omUrMUKnJOo len=0 
' 0018     24 LABEL : Cell Value, String Constant - QBckyFLxE len=0 
' 0018     20 LABEL : Cell Value, String Constant - QCQrx len=0 
' 0018     20 LABEL : Cell Value, String Constant - rmRPI len=0 
' 0018     24 LABEL : Cell Value, String Constant - SqOJIlZHN len=0 
' 0018     26 LABEL : Cell Value, String Constant - TtsyyNTzlHX len=0 
' 0018     21 LABEL : Cell Value, String Constant - ukmJCV len=0 
' 0018     23 LABEL : Cell Value, String Constant - uLCaBHVn len=0 
' 0018     24 LABEL : Cell Value, String Constant - wnEhidxhy len=0 
' 0018     27 LABEL : Cell Value, String Constant - wYaoVkzUuaSY len=0 
' 0018     25 LABEL : Cell Value, String Constant - YbhdRTZSiI 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
' 00f
... (truncated)

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