Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 359aeb01c0240656…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:42:36 Authoring application: Microsoft Excel First seen: 2021-06-28
MD5: ce4feb6b33c5085daf380a50a6171d5f SHA-1: 7e2e0324c9018a2879dae7787219cdc176632ff2 SHA-256: 359aeb01c02406564a9bff0b58dd0ab36032ebb9a5b1a31f64f3316535842ba5
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 macros, specifically an Auto_Open macro. This macro is designed to execute automatically when the workbook is opened. The presence of dangerous formula APIs within the macro suggests it is intended to perform malicious actions, such as downloading and executing a second-stage payload. The document body contains obfuscated text, further indicating malicious intent.

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) 6854 bytes
SHA-256: cc71ab9e489fe4ab6fdd272c88148f84b531ce52c8b7901984916e4d1cc1fd03
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 -  VUVEiooMs
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G188 
' 0018     22 LABEL : Cell Value, String Constant - CDrWTLe len=0 
' 0018     27 LABEL : Cell Value, String Constant - ePcNlQolWjDL len=0 
' 0018     21 LABEL : Cell Value, String Constant - eRndXz len=0 
' 0018     21 LABEL : Cell Value, String Constant - EswLyO len=0 
' 0018     25 LABEL : Cell Value, String Constant - fFJPJAaQRD len=0 
' 0018     22 LABEL : Cell Value, String Constant - gwtNXvW len=0 
' 0018     27 LABEL : Cell Value, String Constant - hBOxvilwlPHA len=0 
' 0018     27 LABEL : Cell Value, String Constant - iLnjumSTgklp len=0 
' 0018     25 LABEL : Cell Value, String Constant - JesUOsBIph len=0 
' 0018     23 LABEL : Cell Value, String Constant - mGJFkCav len=0 
' 0018     20 LABEL : Cell Value, String Constant - MziMy len=0 
' 0018     24 LABEL : Cell Value, String Constant - QydTdDjlg len=0 
' 0018     24 LABEL : Cell Value, String Constant - RDwoqDxls len=0 
' 0018     23 LABEL : Cell Value, String Constant - sqbYLfQz len=0 
' 0018     26 LABEL : Cell Value, String Constant - UJUSRxYezzc len=0 
' 0018     24 LABEL : Cell Value, String Constant - VmmyaaUHp len=0 
' 0018     27 LABEL : Cell Value, String Constant - XZvkzaUJyzVA len=0 
' 0018     24 LABEL : Cell Value, String Constant - yfrXgEpDJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - YkHYF len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZBdjhcs 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
' 0
... (truncated)

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