Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 915ca7bb1a43671b…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:26:23 Authoring application: Microsoft Excel First seen: 2021-06-20
MD5: 9bb2643eb1612e900e14ba0d7c416e0f SHA-1: f4f4e231397ad8d86ec258a6d85ebca23fb47f6a SHA-256: 915ca7bb1a43671bc92ab7ce6976f49bc1d99518c5267b03ff257b157ac2e59a
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 indicator of malicious intent. This technique is commonly used to execute arbitrary code upon opening the document. The presence of dangerous formula APIs further supports this, suggesting the macro is designed to download and execute 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) 6483 bytes
SHA-256: 49f41afdd3b81e37922a8f048fdcb6eaf47ef9ab2c25fc53ba895e482220fa76
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  hcQZZt
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B178 
' 0018     27 LABEL : Cell Value, String Constant - BKokndMBhUFo len=0 
' 0018     21 LABEL : Cell Value, String Constant - dCMTfU len=0 
' 0018     20 LABEL : Cell Value, String Constant - FSKlH len=0 
' 0018     21 LABEL : Cell Value, String Constant - HWwosm len=0 
' 0018     26 LABEL : Cell Value, String Constant - JOgxNTmocQu len=0 
' 0018     23 LABEL : Cell Value, String Constant - KWOopTCs len=0 
' 0018     26 LABEL : Cell Value, String Constant - mNaoTKHUXlc len=0 
' 0018     24 LABEL : Cell Value, String Constant - NheTCaDjP len=0 
' 0018     23 LABEL : Cell Value, String Constant - nvnmrBhr len=0 
' 0018     22 LABEL : Cell Value, String Constant - PNzrdsQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - qCIndUux len=0 
' 0018     26 LABEL : Cell Value, String Constant - qHbrLALHdOa len=0 
' 0018     24 LABEL : Cell Value, String Constant - qYhRTvtiC len=0 
' 0018     24 LABEL : Cell Value, String Constant - SmaWNkuIL len=0 
' 0018     22 LABEL : Cell Value, String Constant - SVCSoiJ len=0 
' 0018     27 LABEL : Cell Value, String Constant - tayamgoRxisJ len=0 
' 0018     22 LABEL : Cell Value, String Constant - UhTTeoh len=0 
' 0018     26 LABEL : Cell Value, String Constant - vwATedfhOkP len=0 
' 0018     22 LABEL : Cell Value, String Constant - XmHGLKz len=0 
' 0018     24 LABEL : Cell Value, String Constant - YweJMZECq 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 
... (truncated)

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