Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9c5907dbb38aea68…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:43:32 Authoring application: Microsoft Excel First seen: 2021-10-01
MD5: 1703082208fd5638a6f3a5983ddae18a SHA-1: e85f35a42faa59e4384dec1732d2751e2d796d94 SHA-256: 9c5907dbb38aea6808aec5413c95ca3bf71c552b177c34108a84c69cbe3bb293
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 function, which is a known technique for executing malicious code when the workbook is opened. The presence of dangerous formula APIs like RUN further increases the risk. While the exact payload is not discernible from the provided evidence, the Auto_Open macro is designed to initiate execution, likely leading to further stages of an attack.

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) 6583 bytes
SHA-256: 04c37ccbd9caad898acfdee72679bb7cf5a92106565781671b3de2e72f0e11c5
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 -  PuyofonGj
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F135 
' 0018     23 LABEL : Cell Value, String Constant - CpvpLwTY len=0 
' 0018     27 LABEL : Cell Value, String Constant - cxWVbRoITbZS len=0 
' 0018     24 LABEL : Cell Value, String Constant - dDvrLpBlg len=0 
' 0018     24 LABEL : Cell Value, String Constant - egjdvBHHa len=0 
' 0018     21 LABEL : Cell Value, String Constant - hvvoiH len=0 
' 0018     20 LABEL : Cell Value, String Constant - IClHj len=0 
' 0018     27 LABEL : Cell Value, String Constant - jAJKmywgUwLn len=0 
' 0018     20 LABEL : Cell Value, String Constant - juEzS len=0 
' 0018     20 LABEL : Cell Value, String Constant - LZetI len=0 
' 0018     24 LABEL : Cell Value, String Constant - MDaGpDkXY len=0 
' 0018     26 LABEL : Cell Value, String Constant - mFWeXLeeFxK len=0 
' 0018     24 LABEL : Cell Value, String Constant - mQEwCQMEV len=0 
' 0018     26 LABEL : Cell Value, String Constant - NbSwbBFPfRG len=0 
' 0018     24 LABEL : Cell Value, String Constant - nGektglDK len=0 
' 0018     22 LABEL : Cell Value, String Constant - PcHjfcB len=0 
' 0018     26 LABEL : Cell Value, String Constant - PYjrDzUEAyh len=0 
' 0018     23 LABEL : Cell Value, String Constant - tAmoliyO len=0 
' 0018     23 LABEL : Cell Value, String Constant - vpAKeXgN len=0 
' 0018     25 LABEL : Cell Value, String Constant - ycbTydvJXa len=0 
' 0018     26 LABEL : Cell Value, String Constant - yPnKCWQQfAz 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
' 
... (truncated)

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