Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8df1b75bb86eb99e…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:38:31 Authoring application: Microsoft Excel First seen: 2021-06-20
MD5: ea85d906b58caabf73e683cbaae76cfb SHA-1: f2d2a4604502b2ca21aac9bfaf024ca769a761be SHA-256: 8df1b75bb86eb99ed78c24c2106c611f02910ad851af45064774e26ada0c9c28
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 upon opening the workbook. The presence of dangerous formula APIs like RUN indicates an intent to execute arbitrary commands. While the exact payload is not visible, the macro's structure strongly suggests it's designed to download and execute a second-stage 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) 6634 bytes
SHA-256: 6abab8788bd6f33342b573d5a0604a9cf9b8182e2d5c195ea08b440a55dd5f21
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 -  wbkqJKTek
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F162 
' 0018     20 LABEL : Cell Value, String Constant - HrBow len=0 
' 0018     20 LABEL : Cell Value, String Constant - HuqqH len=0 
' 0018     21 LABEL : Cell Value, String Constant - iWEmJY len=0 
' 0018     23 LABEL : Cell Value, String Constant - MCEoGOgO len=0 
' 0018     27 LABEL : Cell Value, String Constant - OjjpxfaGaewK len=0 
' 0018     23 LABEL : Cell Value, String Constant - oolWJCQM len=0 
' 0018     26 LABEL : Cell Value, String Constant - pKQQxbhRwxc len=0 
' 0018     26 LABEL : Cell Value, String Constant - SeLDDbBkGXZ len=0 
' 0018     20 LABEL : Cell Value, String Constant - SvrBZ len=0 
' 0018     22 LABEL : Cell Value, String Constant - UVcCtFQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - vutRdUk len=0 
' 0018     27 LABEL : Cell Value, String Constant - wrFGHOXegbYw len=0 
' 0018     20 LABEL : Cell Value, String Constant - wWwBf len=0 
' 0018     24 LABEL : Cell Value, String Constant - xJjAJWkFh len=0 
' 0018     26 LABEL : Cell Value, String Constant - YdFlIFEbuyG len=0 
' 0018     24 LABEL : Cell Value, String Constant - YXSgXRFdt len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZFBhMXqG len=0 
' 0018     24 LABEL : Cell Value, String Constant - zFqYYkxmx len=0 
' 0018     25 LABEL : Cell Value, String Constant - ZoJceRGjqA len=0 
' 0018     26 LABEL : Cell Value, String Constant - zRmYFHVTfmz 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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