Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4b28fc8be26c621d…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:45:14 Authoring application: Microsoft Excel First seen: 2020-12-25
MD5: 552b7b77fdd10c789f9590ae2b0e5468 SHA-1: 4ef7b818ea006d68140b65d143455090ee04aa6d SHA-256: 4b28fc8be26c621de220f0d3852836778f3cceaf781f0b4d1b62d034b3c84e72
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a critical finding. This indicates the macro will execute automatically upon opening the workbook. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary commands, likely to download and run 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) 6638 bytes
SHA-256: d6a4b47b23c50b2aad87014922becf29f4b30dc4b66e33d3cfc15a5e59969761
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  nkKNdUOlLYu
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E172 
' 0018     21 LABEL : Cell Value, String Constant - AyfqZx len=0 
' 0018     23 LABEL : Cell Value, String Constant - ePOfhQBV len=0 
' 0018     22 LABEL : Cell Value, String Constant - gaStsLE len=0 
' 0018     26 LABEL : Cell Value, String Constant - GevmHLnBNpB len=0 
' 0018     24 LABEL : Cell Value, String Constant - IpoxcHebo len=0 
' 0018     25 LABEL : Cell Value, String Constant - KgJgGaJhWp len=0 
' 0018     25 LABEL : Cell Value, String Constant - KpNdbHTLJv len=0 
' 0018     26 LABEL : Cell Value, String Constant - NiiTRbhVPxe len=0 
' 0018     26 LABEL : Cell Value, String Constant - qpNvGmhTvoE len=0 
' 0018     24 LABEL : Cell Value, String Constant - RBjfogKPd len=0 
' 0018     23 LABEL : Cell Value, String Constant - TTwQHZqJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - vryMrU len=0 
' 0018     22 LABEL : Cell Value, String Constant - VrzpDhk len=0 
' 0018     20 LABEL : Cell Value, String Constant - vWQQP len=0 
' 0018     26 LABEL : Cell Value, String Constant - XouegrCWHaj len=0 
' 0018     22 LABEL : Cell Value, String Constant - xpjeZBk len=0 
' 0018     24 LABEL : Cell Value, String Constant - XrUbRXpZz len=0 
' 0018     20 LABEL : Cell Value, String Constant - XtDQt len=0 
' 0018     24 LABEL : Cell Value, String Constant - XzlppomZO len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZLtTkRKiX 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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