Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f558fc8c5af985e2…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:37:53 Authoring application: Microsoft Excel First seen: 2021-07-07
MD5: d30e20f18e0f4c376aae03e082ec1da9 SHA-1: 71321712fd8987f9a652435acd311e5ffeaae0d9 SHA-256: f558fc8c5af985e202f87845babbbd7177cc2fba5793fae163e026e8391a1375
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook. Heuristics indicate the presence of an Auto_Open function, which is a common method for executing malicious code upon opening the workbook. The macro sheet contains references to dangerous formula APIs, suggesting it is designed to perform harmful actions. The exact payload or target of the macro is not discernible from the provided evidence.

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) 6580 bytes
SHA-256: d2f86b52ba4bef49d21ff3cd6b7ea72e1eaf5a32b3262b378fbb2315108a4f0d
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  UfXp
' 0018     20 LABEL : Cell Value, String Constant - ABpJa len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G162 
' 0018     25 LABEL : Cell Value, String Constant - esBXcxrTuo len=0 
' 0018     21 LABEL : Cell Value, String Constant - jdPIUP len=0 
' 0018     27 LABEL : Cell Value, String Constant - osPmywISeoaz len=0 
' 0018     25 LABEL : Cell Value, String Constant - oUMztbcwzf len=0 
' 0018     21 LABEL : Cell Value, String Constant - pNFAZr len=0 
' 0018     25 LABEL : Cell Value, String Constant - qbfbXJSbfM len=0 
' 0018     22 LABEL : Cell Value, String Constant - RETCZAs len=0 
' 0018     27 LABEL : Cell Value, String Constant - siKtwYtXOikD len=0 
' 0018     22 LABEL : Cell Value, String Constant - slyPVQg len=0 
' 0018     24 LABEL : Cell Value, String Constant - tqtASiCTn len=0 
' 0018     24 LABEL : Cell Value, String Constant - TustACKsc len=0 
' 0018     21 LABEL : Cell Value, String Constant - vrMcGU len=0 
' 0018     22 LABEL : Cell Value, String Constant - WakOurn len=0 
' 0018     27 LABEL : Cell Value, String Constant - WIaLNniNrXxd len=0 
' 0018     21 LABEL : Cell Value, String Constant - wLHHWQ len=0 
' 0018     21 LABEL : Cell Value, String Constant - wWNPlb len=0 
' 0018     25 LABEL : Cell Value, String Constant - XFHKwZrHzA len=0 
' 0018     26 LABEL : Cell Value, String Constant - xJhnAYZAGpK len=0 
' 0018     23 LABEL : Cell Value, String Constant - xOyorceB 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     10
... (truncated)

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