Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 54df1850afb1b5fe…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:44:49 Authoring application: Microsoft Excel First seen: 2021-09-23
MD5: 3f637d7b6e0e521150d5789a5dcc7db1 SHA-1: 9536e7c40ace5d51a761e8c13c8a0e6e8d1a6e2b SHA-256: 54df1850afb1b5fe9c5c2d7e9043de796f1438e3538177177d0f7e9b97889e32
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 automatic execution upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary commands. This points to a macro-based downloader or dropper, where the Auto_Open macro is used to initiate the execution chain.

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) 6386 bytes
SHA-256: b9071b35594075fb1f2e2e793ab0754d36a945720c98055521ed9ecebd29b26f
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 -  Lepx
' 0018     21 LABEL : Cell Value, String Constant - AQdHgk len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C146 
' 0018     25 LABEL : Cell Value, String Constant - FvedbjPNUJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - jarkn len=0 
' 0018     24 LABEL : Cell Value, String Constant - JLgbvvyQo len=0 
' 0018     25 LABEL : Cell Value, String Constant - KTjczZYBpQ len=0 
' 0018     27 LABEL : Cell Value, String Constant - mMPzLTaicBQE len=0 
' 0018     27 LABEL : Cell Value, String Constant - nMuUwMIzMfBA len=0 
' 0018     23 LABEL : Cell Value, String Constant - pZnkNERf len=0 
' 0018     20 LABEL : Cell Value, String Constant - QxXkl len=0 
' 0018     26 LABEL : Cell Value, String Constant - RUyApKXQGNt len=0 
' 0018     25 LABEL : Cell Value, String Constant - SXWdqruwur len=0 
' 0018     25 LABEL : Cell Value, String Constant - sZWMFczTkK len=0 
' 0018     20 LABEL : Cell Value, String Constant - tUYqj len=0 
' 0018     20 LABEL : Cell Value, String Constant - uKvpm len=0 
' 0018     21 LABEL : Cell Value, String Constant - umlDPp len=0 
' 0018     25 LABEL : Cell Value, String Constant - VvhnueFXXl len=0 
' 0018     24 LABEL : Cell Value, String Constant - YnHyYezeR len=0 
' 0018     25 LABEL : Cell Value, String Constant - YYuiWZmKLm len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZRixRLIQ len=0 
' 0018     24 LABEL : Cell Value, String Constant - zWwRzBrsY 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     1
... (truncated)

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