Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0bf770688786d93e…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:45 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: fb04415fe419fd9b191a2ecd748bfbbd SHA-1: 8d8cb66ed93c9c42b9cb2ef02584499a094316b7 SHA-256: 0bf770688786d93ee429985d9c8c2ae14ace13fcbdfe4885cfa2cf7f3ed2fb0d
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 finding indicating potential automatic execution of malicious code upon opening. The presence of dangerous formula APIs like RUN further supports this. The macro sheet itself contains obfuscated data, suggesting an attempt to hide its true functionality.

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) 6641 bytes
SHA-256: acb88f1c1c88cad28d1bfbc681f867767e135bf447cd0e9d3c71ebd71065aded
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 -  CgMTwbgdj
' 0018     27 LABEL : Cell Value, String Constant - aDnUDnTMlExN len=0 
' 0018     25 LABEL : Cell Value, String Constant - ahMiXuYIVP len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I159 
' 0018     25 LABEL : Cell Value, String Constant - DqUVIqbuOO len=0 
' 0018     25 LABEL : Cell Value, String Constant - eytaKijLDi len=0 
' 0018     21 LABEL : Cell Value, String Constant - hHCgZS len=0 
' 0018     25 LABEL : Cell Value, String Constant - HULbcmxueK len=0 
' 0018     21 LABEL : Cell Value, String Constant - mrhLgF len=0 
' 0018     21 LABEL : Cell Value, String Constant - nDDAdP len=0 
' 0018     22 LABEL : Cell Value, String Constant - nVjHdQh len=0 
' 0018     27 LABEL : Cell Value, String Constant - ogZLTDeNGdMK len=0 
' 0018     25 LABEL : Cell Value, String Constant - peVtdfmmwn len=0 
' 0018     23 LABEL : Cell Value, String Constant - rDFSeJjy len=0 
' 0018     27 LABEL : Cell Value, String Constant - ReWYveZBnjqu len=0 
' 0018     20 LABEL : Cell Value, String Constant - tUsCN len=0 
' 0018     27 LABEL : Cell Value, String Constant - uBVqsnIaWopa len=0 
' 0018     27 LABEL : Cell Value, String Constant - wVrJOAXVHlZy len=0 
' 0018     26 LABEL : Cell Value, String Constant - WvRlLaljkOd len=0 
' 0018     26 LABEL : Cell Value, String Constant - yxErupaaybT len=0 
' 0018     26 LABEL : Cell Value, String Constant - yZhncjAVPJH len=0 
' 0018     25 LABEL : Cell Value, String Constant - ZRZRVSpvJN 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 
... (truncated)

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